FrankM;

I recently replaced/updated my clothes washer receptacle. Turned the circuit off at the breaker, double-checked it with a multi-meter before working on it and got 5.3v-5.5v, 0 amps. The lights in the basement are on there own circuit and the washer feed was pulled with the feed to this light circuit, so they are in contact for most of the run. Plugged my utility light in, turned the lights on that same circuit off and the voltage reading dropped to 2.2v.
I've recently learned about conductors/Romex being bundled tightly together causing ampacity loss (derating); not sure if it has to do with yours an my "stray" voltage readings, but I'd be interested if anybody out there knows.

Good luck!

ikauffma