While renovating my mother's family room, I need to remove the light fixtures. So I flipped the breaker. The lights went off. I was about to remove and luckily double checked for voltage. I found it was still live. Went back to the breaker switched it on and all the lights came back on. Does anyone have an idea what's wrong with my breaker or is it just a bum current detector?

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    What are you using to test for the presence of electricity? Are there other circuits running through the box for the light fixture in question? Feb 14, 2021 at 20:35
  • I used a non contact voltage tester. The circuit has several lights on the same switch. Feb 14, 2021 at 23:54
  • Ah yes, as others here have called them, the "magic 8-ball detector" which are notorious for giving false readings due to voltages induced by nearby cables. Yet 3phEel makes a good point, there may be more than one circuit there. Not likely, but possible. The fact that the lights went out when you turned off the breaker tells us that the breaker is operating properly, but again, it's remotely possible there is more than one circuit there. Can you post a picture of the fixture box BEFORE you take anything apart? Feb 15, 2021 at 0:00
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    Yes, can you get us photos of the inside of the fixture box please? Feb 15, 2021 at 0:43
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    Does this answer your question? Unexpected voltage with switch turned off
    – FreeMan
    Feb 15, 2021 at 19:20

1 Answer 1


What you are seeing is called phantom voltage. This is a voltage induced from another live circuit that is running parallel to your now dead circuit.

Proof the breaker worked all the lights went out.

Phantom voltage is a voltage and depending on several factors it may be 120v but there is no current potential thus the lights are out.

There is a possibility that this could be part of a multiwire branch circuit And the neutral is conducting the other circuits power back to the source. And that’s why multiwire branch circuits require handle ties by modern code.

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    Duplicate (several times over), right? The question should be flagged as such.
    – isherwood
    Feb 15, 2021 at 19:17

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