Just to clarify a few points . . .
1. I'm talking about a Sqare D 15 amp GVCI circuit breaker. The GFCI
is provided at the breaker, not on a receptacle.
2. I checked the voltage at the wire lug on the breaker several times
and flipped the breaker on and off to verify that the voltage drops to
zero when the breaker is off. By the way, the digital tester
apparently doesn't carry enough current to trip the GFCI when I tested
the voltage from wire lug to ground.
3. All the wiring in the house is copper. This circuit happens to be
14 gauge copper. The house was built in 1976 with 14 gauge wire and a
single GFCI breaker serving lights and receptacles in two bathrooms,
two receptacles in the living room, two kitchen counter receptacles by
the sink and two outside receptacles. Several years ago I split the
circuit, added a second 20 Amp GFCI breaker, and ran 12 gauge copper to
the OTHER bathroom because a hair dryer in either bathroom dimmed the
lights so much, and two at once would trip the breaker (DUH). Without
so many loads on the wire, the 20 amp circuit doesn't dim at all with
the hair dryer, and the 15 amp dims just enough to notice if you're
My main question was whether the most likely culprit was the old
receptacle with stab-in connectors or a loose connection at the
breaker. I think you've convinced me it was probably the receptacle.
Thanks for all the replies.
"Every man is my superior in that I can learn from him."