Measuring a downstream GFI plug
Hi, I was wanting to tie into my plug receptacle that supplies power to my garage door opener. It is in the ceiling and is apparently supplied by my garage gfi receptacle. I turned off the supply breaker to this and tied into the ceiling plug. I measured phase to phase and was alarmed that i had continuity from black to white. I did not think this was normal. Is this a function of the gfi circuit??