Rampy wrote:

Not being an electrician, I'll do my best (and appreciate the help)...

Two sets of wires enter the box, each with white, black, ground. I
determined the line set by leaving only one set of the wires connected
to the outlet, powering on at the breaker box, and seeing that power
still flowed to the outlet. I didn't test the other pair, but assumed
them to be a load. The grounds are all bound together and connected to
the common copper ground on the box and to the outlet ground. Line in
at the top, load out at the bottom. Sorry, but I don't really have
information beyond that. Thanks again for the info.

Without any insult intended, do both the black wires go to the brass
screws on the GFCI and both the white wires to the silver screws? (Or to
the screws marked with letters like L and N?)

Failing that not being correct, I'll side with what trader4 just said,
the problem is downstream. switch off the breaker and take that hall
light off it's box and tell us what you find. You didn't say whether
that hall light was controlled by a wall switch or a pull string,
(Unlikely, huh?) but if it's a wall switch open that up and look for
anything unusual there too.

Good luck,

Jeff


--
Jeffry Wisnia
(W1BSV + Brass Rat '57 EE)
"Rudeness is the weak man's imitation of strength."