How To Figure Out What A Light Switch Goes To?

There are times when you find yourself in a room with a mysterious wall switch. Unfortunately, it isn’t easy to figure out what the switch does as you flip it up and down.

The wires behind the wall may be easy to follow if you have electrical training, but there is a more cost-effective and easier way. Find out what your switch does with a low-tech method.

Steps To Figure Out What Wall Switches Might Do

Steps To Figure Out What Wall Switches Might Do

It’s first important to determine whether wires are connected to the switch. Taking off the faceplate will probably reveal this information. You should also check both the outlets at the top and the bottom.

Taking a look at the wiring of the switch is the next step. Start by turning off the circuit breaker and testing again with a non-contact tester. To be safe, the box may have more than one circuit if you don’t know what the switches do.

Take note of the switch type after removing the switch. What type of switch is it? Is it a single pole or a three-way switch? Identifying what is controlled by a 3-way switch might be as simple as looking at the color of the traveler. Does this box house the circuit breaker line?

The circuit must be traced if a visual inspection doesn’t reveal anything. An electrical circuit tracer is usually used with the power off. Many cases can also be solved with a telecom probe or tracer.

It may also be the case that the outlet or plug on an outlet is being switched. For example, when the floor lamp in a room is switched on and off, it isn’t uncommon for only the top plug to be switched on.

A scope or opening of the wall might be necessary to help trace the wire, depending on how badly you want to know.

Examining The Wiring In The Outlet

Examining The Wiring In The Outlet

You still have the option of checking each outlet’s wiring, whether or not you use a wire tracer. But first, be sure all the wires surrounding the outlet are connected adequately after removing the cover plates.

You may have disconnected an old wire. Light switches would be unable to function correctly if this were to happen.

However, the wires can be connected if this is the case, and you are comfortable doing so. It should then be possible to control the outlet with the switch.

Alternative Method

Don’t forget to turn off the power to the room you’re working in as a safety precaution.

Alternative Method

Duration: less than 30 minutes

Cost estimate: $50 or less

Step 1: Check if there is electricity at the switch. You can purchase an electrical tester in the hardware store for $10 to $30. Take all necessary safety precautions after turning off the power.

Step 2: Remove the switch plate from the switch, then open up the switch.

Step 3: Check to see if there is a red wire. If so,

Step 4: Check each outlet in the room to see if it also has a red wire. Those are the outlets that are connected to the switch.

Step 5: Unscrew the two screws holding the outlet to the wall.

Step 6: Find the “outlet tab” between two screws on the side of the outlet. Alternatively, you can find images online of the “outlet tab.”

Step 7: Wiggle that tab back and forth with pliers (needle noise would work best).

Step 8: Check that all wires are rightly connected.

Step 9: Assemble the wall by reinstalling all the components.

Step 10: Once the power is restored, test the switch.

It should now be possible to have one plug always hot and one controlled by a wall switch. It may also be necessary to replace the switch if that does not resolve the problem.

The wires most likely need to be inspected somewhere between the switch and plug if that still does not work.

Using The Lamp Method

Using The Lamp Method

This simple, low-tech method is one of the oldest yet most effective ways to solve a problem. To begin with, make sure that none of the light bulbs in the fixtures are dead.

Replace any faulty switches by turning them off and swapping them out. After that, make sure all the bulbs are working again by turning the switches back on.

Shut off all the light switches once you are sure the bulbs are working. It’s best to get a lamp that’s small and easy to move between outlets. It is important to ensure that the light is on.

Once plugged in, turn the switch on various outlets until the bulb lights up. Once that happens, you have located the light switch control outlet!

To avoid accidentally shortening the bulb, shut off the switch after removing the plug. You can try another method if you have plugged the lamp into every outlet in the room, but it remains unlit.

Wire Tracers: Finding the Right One

Wire Tracers: Finding the Right One

You’ll want to find the best wire tracer when testing your light switch.

Wire tracers manufactured by trusted manufacturers like Ideal Industries or Klein Tools are the best choice. In addition to the wire tracer’s characteristics, you should pay attention to its features.

How good are these features in terms of sensitivity adjustment, penetration capacity, and transmitter power? How durable is it? Last but not least, you need to be able to afford it.

Get An Electrician To Help

Call an electrician when all else fails. They will resolve the problem. Also, professionals can solve wiring issues if you have one.

Is There A Maximum Amp That Should Be Used For A Light Switch?

A 15-amp switch is acceptable if one or two lights are connected. However, a 20-amp switch is required for more than two lights.

Light switches: How Do You Know Which Wire Is Which?

Adding the wires to the switch correctly is essential if you want the switch to work properly. A white wire should come down from the ceiling that is hot. In addition, the black hot wire should be aimed upward.

Flipping A Light Switch: What Happens?

By switching on and off, the circuit is essentially opened and closed. A closed circuit allows electricity to flow through the wires and power the fixture when the switch is on. An open circuit cannot be transmitted when the switch is off.


If none of these methods work, there may be a problem with the wiring in your switch or a switch that is mis wired. Check with an electrician if you’re unsure.

There may be an optional fan in the room’s bottom of a gas fireplace that this switch controls.

Final Words

Most houses have that one light switch that doesn’t do anything. You may find it quite frustrating. Not to worry, though! It is possible to find out what your mystery switch controls in a few different ways.

You can use a lamp as a tester by plugging it into various outlets and flipping the light switch until the lamp illuminates. The light switch’s circuit can also be traced using a wire tracer device.

If any disconnected cables are in the room, open all the outlet boxes. Then, even though you may not be able to fix the issue, you will at least be able to identify the wire.

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