Any time you need to drill into the wall, you need to know the location of the electrical wires.
Drilling into a wall without this knowledge can result in electrocution.
You may also drill into your plumbing.
You need a way to locate the electrical wires in your wall.
How To Find Electrical Wires In Walls (Step-By-Step)
There are three main methods to use to find electrical wires behind standard drywall.
You’ll need to use a few different methods to find electrical wires in concrete walls.
We found several different methods to help you find electrical wires in your walls no matter their material.
Follow these steps to find them safely.
Method 1: Electrical Wire Detector
This method requires the use of an electrical wire detector.
There are several types available.
Some are better at detecting through certain materials than others.
They also can detect other objects in the wall like plumbing and wood.
An electrical wire detector works by emitting a signal through the wire.
This signal acts as a probe.
In some cases, the wire you’re looking for needs to be live for the detector to work.
Others don’t require the wire to be live.
These detectors tend to be less expensive than live-wire detectors.
As a safety precaution, if the detector doesn’t need the wire to be live, then you should turn off the power through the circuit breaker.
Once the probe passes through the wire, the receiver picks up on it.
The device will make a noise, light up, or give you a visual indication that there’s a wire at that location.
Follow these steps to use an electrical wire device the right way.
Step 1: Buy The Correct Electrical Wire Detector
Stopping by the hardware store, you’ll find there are tons of different electrical wire detectors.
They classify as stud finders, so you’ll find them in that section of the hardware store.
When shopping for your electrical wire detector, consider the material of your wall.
If it’s drywall, then any basic electrical wire detector will do.
If it’s concrete or something else, then you may need a special detector.
You should also consider if you want to find anything else inside the wall.
Many detectors can tell you where the plumbing is in the wall as well.
If this is a feature that you want, then it may be worth the extra expense to find a detector capable of performing this function.
One final consideration to make is if you care whether the wire needs to be live or not.
If you’re wary of keeping the power on during your search, then you want to find a non-live electric wire detector.
If you don’t mind the wires being live, then you can choose a live wire detector.
Non-live wire detectors are cheaper than live wire detectors.
Otherwise, you only need a basic electrical wire detector that will tell you where the wire is in the wall.
Step 2: Plug The Transmitter Into The Outlet Near The Inspection Area
Standard electric wire detectors have a detection range of three meters.
You need to be as close as possible to the area that you want to search.
The closer you are, the more accurate of a reading you’ll receive.
Open your electric wire detector’s box.
You’ll find it comes in two parts.
The transmitter delivers the probe through the electric wire.
The receiver picks up on the probe when it nears it in the wall.
The transmitter is the part that connects to an outlet.
Plug it into an outlet that’s closest to the inspection area.
You may find that more expensive detectors have a wider detection range or offer more accurate results.
Step 3: Turn Transmitter And Receiver On
After the transmitter is in the outlet, you need to turn on both the transmitter and the receiver.
This is as simple as finding the power button and pressing it.
Consult the manual if you can’t find the power button.
Step 4: Use The Manual To Find How To Hold The Receiver
To receive accurate results, you need to hold the receiver the correct way.
Some receivers need to be flat against the wall to detect the probe in the wire.
Others need to be held at an angle.
The manual will tell you which way to hold the receiver to give you a clear result.
Step 5: Transmit A Signal
Press the signal button on the transmitter.
It will start to deliver a probe, or signal, through the wire in the wall.
Use the receiver to find the signal.
Move the receiver in a horizontal direction to find the probe.
That’s because electrical wires run horizontally and vertically through the wall.
Step 6: Look For The Signal
It can take some time to find the wire.
One tip is to start at the outlet and move slowly from there.
You can also search the area that you intend to push a nail or screw through.
When the receiver detects the probe, it will alert you.
The alert may come as a noise, the receiver could light up, or it might give you a visual cue.
Keep an eye on the receiver, so you don’t miss the signal.
Once you see a signal, mark the location with a pencil on the wall.
You now know that there’s an electric wire in that location.
Method 2: Magnetic Stud Finder
Another method is to use a magnetic stud finder.
This device is useful because it helps you find nails in the studs.
Studs are wooden beams, sometimes metal beams, which hold up the wall.
The magnetic stud finder locates the metal beam or the nails in the stud by generating a magnetic field.
This helps find wires because the wires often rest on the nails in the studs.
Follow these steps to use a magnetic stud finder to find electrical wires in walls the correct way.
Step 1: Buy The Right Magnetic Stud Finder
Like electric wire detectors, there are several types of magnetic stud finders.
You need to find one that best serves the purpose you need it for.
Some stud finders are more accurate than others.
These tend to be more expensive.
Others can also detect other materials in the wall like wood.
To ensure you make the job easier, buy the magnetic stud finder that is specifically made for the job you’re using it for.
Step 2: Consult The Manual
When you get your magnetic stud finder back home, take the time to read the manual.
In particular, you want to understand how to hold the stud finder.
Like the electric wire detector, if you don’t hold the stud finder the right way, then it can reduce its accuracy.
Magnetic stud finders can only sense so deep within a wall.
You need to do everything you can to increase its accuracy.
Step 3: Turn The Stud Finder On
If your stud finder needs power, then switch it on.
Not all magnetic stud finders require power to use.
You can hold it against the wall and start searching.
Once it’s on, hold the stud finder against the wall according to the instructions given by the manual.
Move the stud finder in a horizontal direction.
The wires run horizontally in the wall.
Step 4: Look For The Signal
A magnetic stud finder works by detecting the metal in nails or screws within the wall.
When it detects metal, the device emits a signal.
You need to look for that signal to determine where the nails are in the wall.
Sometimes the detector will light up, emit a sound, or have a visual cue that tells you it’s detecting metal.
Step 5: Mark The Area
Any time your stud finder goes off, mark the area.
You end up with a general idea of where the nails are in the wall.
This tells you that there’s a possibility that the wires are there, too.
You can either use an electric wire detector for more accurate results, or you can carefully start to nail it into the wall.
Method 3: Hole And Camera
This method is ideal for homeowners who don’t mind damaging their walls a little.
If you want to know what’s going on behind your wall, then the easiest way to tell is to actually see behind it.
Using a flexible scope camera can help.
Follow these steps to put a hole in the wall and use a camera to find electrical wires in the walls of your home.
Step 1: Buy The Right Flexible Scope Camera
It’s going to be dark inside the wall.
There may be some light coming in from your house.
However, you should plan on it being dark.
You need a flexible scope camera that has either night vision or a flashlight attached to it.
Flexibility is also important.
It allows you to turn the scope in tight corners to get around obstructions.
You should also consider the quality of the camera.
If the video is grainy, then you may not be able to tell what’s an electric wire and what’s visual feedback.
Consider making a large investment to receive the kind of results that you need.
Step 2: Carefully Cut A Small Hole In The Wall
Before you cut into the wall, turn off the power.
You can do this by going to your circuit breaker and turning off the main breaker.
This will stop the flow of power through your house.
You can now safely cut a small hole in the wall.
The hole should run parallel to the area that you want to inspect.
It doesn’t need to be a large hole.
It just needs to be large enough for the scope camera to fit through.
You can use a utility knife to cut through drywall.
Go slowly to avoid cutting through unexpected wires or plumbing.
One tip is to avoid cutting near an outlet.
Step 3: Insert The Camera
It’s a good idea to mark the cable every few inches with some tape.
That will tell you how deep the camera is in the wall.
Then you can measure on your side of the wall to determine its location.
Once you’ve made the marks, you can insert the camera through the hole.
Go slowly and point the camera in the direction of the wall that you want to inspect.
Watch the screen to steer the camera the right way.
Look for electric wires that run horizontally across the wall.
Step 4: Mark The Area
Using the marks you made on the cable, measure on your side of the wall where the camera is.
Then mark with a pencil on the wall where the wires are.
You should have a pretty clear idea of where the electrical wires are now.
Remove the camera back through the hole.
Step 5: Patch The Hole
If you made a small hole for the camera, then patching it is easy.
Use standard drywall plaster to fix the hole.
Then paint it to match the rest of the wall.
How To Find Electrical Wires In Concrete Walls
While searching for electrical wires in standard drywall is easy, finding them in concrete walls is a lot harder.
Concrete walls are substantially thicker than drywall.
The stone also makes it difficult for signals to pass through it.
Yet there are a few methods you can use to find electrical wires in these walls.
Follow these methods to do so safely.
Method 1: Consult Blueprints
You may not even need to open up the wall or buy any devices.
Finding electric wires in a concrete wall may be as simple as locating the blueprints for the building.
You may need to speak with your local county to see if they have the blueprints in their records.
They may also be able to help you contact the builder.
Acquiring the blueprints will include the electrical work.
You can see where the wires are on the blueprints for the specific wall you need to inspect.
This method requires a bit of running around, but it will save you money in the long run.
Method 2: Use Logic
Another method is to think logically about the setup of the electrical work.
You know where an outlet is in the wall.
You also know that wires run horizontally in the wall.
That allows you to deduce an approximate location of where the wires are due to the proximity of an outlet.
Before you start drilling through the wall, turn off the power just in case your estimate is wrong.
Method 3: Purchase A Concrete Stud Finder Or Electric Wire Detector
Some electric wire detectors can detect wires through concrete walls.
They tend to be more expensive than other types of wire detectors.
Consider the thickness of the concrete wall when choosing your electric wire detector.
Some stud finders can also penetrate through concrete to detect metal.
You can choose either type of detector, but you need to make sure that the one you choose is capable of penetrating concrete walls.
Step 1: Plug Electric Wire Detector Into The Outlet Or Hold Stud Finder Against The Wall
Depending on the device that you chose, you need to first plug the electric wire detector in the outlet.
For a stud finder, you need to turn it on or hold it against the wall.
Activate the signal in the electric wire detector.
Step 2: Place The Receiver Or Stud Finder Tight To The Wall
You want to eliminate as much distance as possible between the receiver or stud finder and the wire.
Press the device tightly to the wall and look for a signal.
As with standard drywall, move horizontally and look for a signal.
Step 3: Mark The Area
When the signal goes off, mark the concrete wall.
You can’t be 100% sure that the device is accurate.
As such, never open up the wall without first turning off the power.
How To Find Electrical Wires In Walls When A Wire Is Broken
Because certain detectors require the wire to be functioning, you may find it difficult to find an electrical wire if it’s broken.
There’s still a way to find the electrical wire even if it’s broken.
You need to use a circuit tracer.
Follow these steps to use a circuit tracer to find an electrical wire that is broken.
Step 1: Plug The Circuit Tracer Into The Outlet
Like the electric wire detector, you’ll plug the circuit tracer into the outlet.
The outlet needs to be close to the area that you want to inspect.
Turn the circuit tracer on and activate it to emit a signal.
Step 2: Run Receiver Along The Wall
While the transmitter is producing a signal, run the receiver slowly along the wall.
You’ll notice that it receives a signal any time it finds a live wire.
Follow the wire with the receiver.
Step 3: Search For A Loss Of Signal
While you’re following the wire with the receiver, you may discover that the signal disappears.
If it only disappears in one place or for an extended time,
This indicates that there is a broken wire.
Mark the area.
You now know where the broken wire is and where the live wires are.
Step 4: Turn Off The Power And Open The Wall
Turn off the power to keep from accidentally nailing into the wires.
Then open the wall in the marked area where the broken wire is.
Replace or splice the wire as needed.
Drill or hammer into the wall as needed.
There are several methods you can use to find electrical wires in walls.
Even thicker walls, like concrete, have a few ways that you can use to find the wires.
Use these methods and steps to find your electric wires and install shelves the safe way.