Sounds like a question for an electrician. You might consider posting this question on an electricans forum. I can tell you this, there was a plumber who was recently killed who was laying in water and grabbed a copper pipe. I dont remember all the ins and outs of the story but the bottom line was an incorrect grounding connection is what killed him. There was something wired wrong in the house panel and there were several sections of copper pipe missing so that the power being sent thru the pipes was never noticed until this poor plumber provided a method for the power to run to ground. Im not saying that you have this kind of problem, I truly have no idea... That being said, IMHO you should consult a local electrician for your best possible result.