the other day I was adding a GFCI outlet to a friend's bathroom. There is a fan switch on the opposite side of the wall so I decided to tap into it's power. I installed an old work box with the ears, screwed in the GFCI outlet, ran the wires using Romex into the fan switch box. I connected all the whites first but not the ground which was a mistakes but I don't think it would have caused this problem. There were two hot wires screwed together and when I went to attach the GFCI black wire to the two hots, I got a little spark then the lights and all power went out including to the other GFCI in the bathroom.
I checked the electric panel but saw no tripped breaker. I also tested each breaker with a contact tester and they had power. There was one breaker that was off but it had no wire going into it which you'll see in the pic. I talked to an electrician over the phone and sent him relevant pics and he didn't see a problem with the way anything was wired except for the ground. I went through the entire house to check the GFCI's and they all worked. I disconnected the new GFCI and wired everything back to the way it was before but still have no power.
Is there anything else I can do before an electrician has to come out?
I checked the electric panel but saw no tripped breaker. I also tested each breaker with a contact tester and they had power. There was one breaker that was off but it had no wire going into it which you'll see in the pic. I talked to an electrician over the phone and sent him relevant pics and he didn't see a problem with the way anything was wired except for the ground. I went through the entire house to check the GFCI's and they all worked. I disconnected the new GFCI and wired everything back to the way it was before but still have no power.
Is there anything else I can do before an electrician has to come out?