Hey there Lake, When ever I thawed pipes in the past, I have a water key put down out front at the road, I then went inside the house and hook to the pipe as it enters the house.

I totally agree don't hook onto the pipe just anywhere in the house because electricity might hop on a ground wire inside the house inside the wall, So I get that, That's a no brainer for me.

However, I never thought about the possibility of plastic being added, So now the electricity goes out to the pipe in the road, over to the neighbors, runs through the neighbors water pipe, takes the path of least resistance which turns out to be a wire ground in the wall goes outside up on the telephone pole down into the house you are trying to thaw water for in the first place, then catches a ground wire in that house and then down to the welding cable making it possible to burn down 2 houses.

I think that's what your trying to say.

I'm pretty sure that it would be pretty unusual but its nice to know what could happen, I will go back and read some more about checking the ohms, Thanks for every ones input.