I remember borrowing 2 radios a Murphy B41 and B40 these were ex marine sets which improved my listening experience no end. However I soon found out that both radios chassis were live to earth i don't know by how much i didn't have an AC voltmeter at that time. I do know that there were no incorrectly wired plugs or sockets i checked carefully also the first time i got a shock the sets were in a temporary location not in there final place in my shack. The estate were i lived then had OH 5 wire distribution all round fed from ground mounted TXs interestingly I found out later that someone who lived the other end of the same estate had a similar problem getting shocks from taps and metal kitchen sink units they were fed from a different TX although I think the neutral on the pole was continuous all the way round what in your opinion mite of been going on? The radios had transformer PSUs so were supposedly isolated internally from the mains