[DanDaMan]

So I have been replacing old plugs and switches in my house. Being my breaker panel is not labelled and that I didn't want to shut power to entire house, my process has been to trip breakers one at a time while my wife uses a NCVT until power is off (it stops beeping). I then change out the plug switch and repeat. I was about 99% done until I got to my last plug and switch (they are in line of each other). This time though the tester kept beeping even after I tripped every breaker in the house. I then went to turn the main breaker switch off (no power to entire house), and the tester would still beep at this switch and plug. I got my multimeter and conmfirmed no power. I even got a power drill and plugged it in and sure enough no power. But tester goes crazy if I put it near the plug or switch. There is also a light wall scone near the switch and the tester goes crazy there too.

Any ideas why the tester gives me a false positive? Thanks

 

[roughneck]

Is there any electrical current in that area?
Or is the main run near there?

 

[DanDaMan]

Is there any electrical current in that area?
Or is the main run near there?

No, the area is in the back yard one the edge - the power coming into the house is in the front on the other end of the house. I looked outside (where this tester goes crazy with), and there are no wires.

It is very strange.

 

[RAL238]

Non contact voltage testers are unreliable and every one I've seen will give a false positive reading in some cases. Some brands are better than others, but we're just talking about one brand being a little less unreliable than another. They're very good at telling you when the power is on. Not so good at indicating when it is off.

It's possible your circuit is picking up something because the wire runs near the main feeds in your panel. No good way to tell for sure.

 

[roughneck]

I’d be inclined to believe the meter more then the non contact tester.

 

[darren]

I prefer a plug tester like below when the receptacle is still in place. A radio or power tool will do the same thing.

I usually use a non contact tester when I am dealing with wires that have nothing attached to them.

https://www.alphacontrols.com/ST-10...MI6_qctLT16AIVzZ-zCh3tlwasEAQYASABEgIK6vD_BwE