How to Use a Voltage Tester on a Light Switch?

Why did that light suddenly stop working? — this is something most of us have uttered in our lives. What makes it even more baffling is that the light itself seems to be fine. So, now, the task turns into finding out what went wrong.

At that point, you need to check out whether the switch and its wiring are working fine. But how to use a voltage tester on a light switch, you ask? Well, we are going to be answering that in this article. Along with testing your switch, you will learn about different components as well.

Different Types of Testers

Types of voltage Testers

Here’s the issue – there are a lot of voltage testers. In a lot of cases, using them is totally different from one another. If you still have not bought one, that’s fine. You can choose the suggested ones and follow the guide.

However, if you already have one of them and are trying to work with it — we cannot possibly know which one it is. To make sure that you can still follow us, let’s talk about the typical testers to help you figure them out without an electrician.

Non-Contact Voltage Testers

Non-Contact Voltage Testers

These are the safest and most convenient testers to use. A non-contact (AKA inductance) tester does not require you to touch any electrical parts or wires to check for voltage.

To get a reading with a non-contact voltage tester, all you need to do is get its tip close to the outlet or just touch the outside of the wire, if that is what you are trying to check.

Tools like this rely on batteries to power themselves. A lot of them even come with a torch in the front to help you in the dark. All in all, they are quite convenient. And there is a light on them to show whether current is flowing through the wire/switch.



When it comes to electrical testers, multimeters are one of the most popular ones — especially for professionals. These do not just show the voltage, however. You can get readings for voltage, capacitance, and continuity as well.

As you can see, these are the swiss army knife of testers. But these are not non-contact testers, meaning you have to touch a wire if you want to test its properties.

You can use the test functions on these and choose which reading you want. This ability provides you with much more granular control and very specific readings.

Plug-In Circuit Analyzer

Plug-In Circuit Analyzer

These are some of the most affordable ones you can buy. All you have to do is plug them into the outlet in question, and you can find out whether the circuit is fulfilled. There is a bummer, though.

Your outlet needs to have three slots to use one of these. As you know, these have three wires — a ground wire, a neutral wire, and a hot wire. A plug-in analyzer requires a grounded outlet to function. There is a solution to that below.

Neon Voltage Testers

Neon Voltage Testers

We have a rather simple but adequate device at this point. These testers only have two wires with metal probes at the end. And as the name suggests, it includes a neon light as the indicator.

If the connection is working fine, then it lights up. The good thing is that you need not worry about ground wires or batteries for these. Plus, they are inexpensive and get the job done.

Testing the Light Switch

When it comes to a voltage tester, these are the common ones. There are a few other types, but those are not as widespread. With that out of the way, let’s get to the testing bit.

Testing the Light Switch

Disconnecting and Taking Everything Off

Firstly, make sure that you have turned off the power to the outlet(s). To be certain, turn off the breaker (or remove the fuse, depending on your house) of the respective outlet.

Once you have done that, you can return to the switch. Now, unscrew the cover plate and take it off. Even though the breaker is turned off, use a tester (non-contact recommended) to check if there is any electricity flowing through it.

If it shows that it is completely disconnected, you can move on to the next step. But if it does not, make sure you have got the right breaker. Afterward, we will remove the switches.

Remembering the Positions

Remembering the Positions

When you remove the mounting screws of the switch and take them off, make sure you know what is what. If there are only two terminals on both sides, then it is a single-pole switch.

If it has three terminals, however, it is a three-way switch. The one that is colored black needs to be exactly where it was when you reconnect it; the other two would still work if you altered their positions. For the next step, get your continuity tester handy.

Testing the Continuity

If you have a multimeter, turn the dial to the sign that shows ohm (AKA the measurement of resistance). You can get an audible signal from it too. But if it is a simple meter to test continuity, then there is no issue of that sort.

For switches with only two terminals, clip one wire to one of the terminals, and touch the other one with the tester’s probe. If the switch is turned on, the meter should stay close to 0, meaning it has continuity.

As you can guess, the number should be near 1 when the switch is turned off.  For switches with three terminals, clip the wire to the black (or any dark-colored) terminal, and then touch the probe to any of the other ones.

Afterward, try the other terminal while keeping the black one connected and follow the same procedure to see if the switch is functional.

Testing the Continuity

Putting Everything Back

If the switch did not pass the continuity check, you need to change it. Make sure that you have got the same voltage and other ratings as the previous one.

After you have done that, connect the wires (with the breaker still off) and tighten the screws properly. Once that is done, put the switch back to its place, and screw everything back together.

As we are done with putting the receptacle and covering plate back, we can turn on the breaker or reconnect the fuse. If a faulty switch caused the problem and you connected everything properly, it should all be fine again.

Use of Voltage Tester on a Light Switch

Final Words

We hope you have been able to follow the guide easily. If you have, then asking how to use a voltage tester on a light switch should no longer be necessary. And yes, remember to maintain precautions.


My name is Michael M. Militello, and I want to help you find the right tools and the best products for your next project! As a professional tool expert here in Houston, TX, With my vast tool experience, I can help you choose the right brand, model, and size for the job. Please feel free to contact me with any questions you may have. You can reach me here on my blog and also on Facebook, Twitter , and Pinterest. I look forward to hearing from you!

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