My house had a ground problem and something else wrong and I would get shocked in the shower all the time. My whole setup got fried to. It took the electrician almost a month to figure out the problem and fix everything. He replaced all the switches and plugs near the shower, swapped the breakers to gfis'. I had to take a bath with a bucket so I wouldn't shock my self.

He ran a new ground wire for the breaker panel and when he was tying it into the ground round it turned out to be a piece of rebar only about a foot deep. He replaced it with a like a six foot ground rod. It turned out that the main wires from the Utility pole got loose inside the meter box and was shorting out against the box but since the ground wasnt good it passed about 60 volts thru everything hooked up to ground.