OK so my pal and I were playing with his new R-Tech AC tig set in the garage, got a few reasonable beads before running out of gas. Strange thing happened, as we're welding, my wife comes to the garage door telling me the speakers in the TV and hi-fi are humming and our power shower has just switched itself on !! Now what the hell is all that about ? We put it down to some high fequency interferance but has anyone else had any issues like this in a residential setting ?