I did the wiring on a newbuild a few months ago, and today the electric meter was fitted. The job was all ready to finish as my CU tails were waiting in the meter cupboard to connect to the isolator that the eletricity co have supplied.
Whilst I was fitting the tails my apprentice pointed out that there was a kettle plugged into a socket in one of the bedrooms and when he turned it on it worked. I went to look and so it did. A look around the house found an extension lead from a neighbours house passing (trapped as the door was shut) under the UPVC back door and then from the extension was a lead made up of two plugs at each end.
This "lead" had one end plugged into the the extension lead from next door and the other end into a socket in the house and to make matters worse it switched the live and neutral so the house sockets had reversed polarity
What would have happened if I had powered up? I have not yet checked to see it the two houses are on the same phase.
Adam
PS It was the decorator that did the extension lead bodge, a friend told him how to do it and therefore have the sockets powered up for a light, radio, kettle etc