Voltage feedback(current)
I work for a cable company and we have this phenomenon called voltage feedback. It breaks down into two parts. First part is we read an AC voltage between the coax and house ground, which we say is "floating voltage". Second part is where we grab the coax and touch the ground and get a "tingle". Sometimes we can attribute the tingle to a bad electrical plug, bad t.v. etc. but sometimes, none of these apply and we are baffled. Any more knowledge would be extremely heplful.