Energized area around receptacles

Before I explain this, the report is done and of course recommended further evaluation and I have moved on.
While doing an inspection yesterday as I always do with two pronged receptacles tested for power with a touch voltage tester. Before I was even close to contact the tester lit up. I started experimenting and checked the drywall around the receptacle and the drywall appeared to be energized all the way around the receptacle about 6 inches. I alway have a spare tester with me and double checked with the backup and the same result. I checked every receptacle and switch in the room with the same result. I checked every receptacle and light switch in the rest of the home and it was only the one room. The buyers brother who was a licensed electrician was present and had no idea what the cause would be. Just looking to se if anyone else has ever seen this or knows what would cause it. I always like to know when possible.

That’s why I carry 2 testers with different sensitivity.

Pretty surprising, as induced voltage and other “false positives” with a non-conductive tester are a common and well known condition.

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Typically this occurs when the outlet is un-grounded (we already knew that) AND it is in a metal outlet box (also un-grounded). The outlet box changes (enhances) the capacitive coupling of the “sniffer.”

Understanding Capacitive Coupling


Great article, Bob!

On those old 2 prong receptacles, I used a voltage tester like below. I would insert the red prong into the small slot and pinch the black prong between my thumb and index finger and if it lit up, I thought it was wired correctly. But if I inserted the red into the larger slot and it lit up, I knew it was reverse polarity.

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That’s how I test for reversed polarity+bootleg ground. If you pickup high potential on the ground leg, you know you have a very very dangerous and unethical wiring. Normal testers will show the receptacle as 100% wired correctly.

Great mind you have there, Simon. :smile:

Some of those tickers are too sensitive… If they are too sensitive they’re useless to me… and will start blinking about a foot away…I like the ones where they don’t go off unless I slip one side into the hot side of an outlet. I find some of the cheaper brands are better…

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I’ve had the same experience, Ray.

What years the build.
What type of wiring? K&T?

No ground on outlet.
Look were you have your tester, voltage sniffer. K&T run 90 degree cables on framing memebers.
You are sniffing 90 degrees of the terminals.

Wiring is close to the drywall / Plaster Lathe with K&T at times.
Buy a better voltage sniffer. Fluke 1LAC II A Non-Contact Voltage Tester. At the very least know the range you are sniffing.

Test to insure a neutral and a hot are present with that type of receptacle.

Too cheep. Like a Three Bulb Tester.
Too bad. So sad, cheap for the client.

Love my wiggly!

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I learn something new every day from you guys!

We all learn here, Scott. Even us old birds. :smile:

That is what this forum should be all about.

I use this when I can’t figure it out on my own.

Not on the job I hope.

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I use the same. Also an Ideal tester for two-prong receptacles.

Back in the old days, I used to stick my screwdriver in the narrow slot of a two prong receptacle then test the shaft with the tick tester to check polarity.

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I use the EXTECH 80. AFCI and GFCI circuit load tester, Good choice. Yep.

Great info.