When I bought my house I had the electrician add some power points. he was concerned cause the earth seemed problematical - it was connected to the water pipe feed from the street. What we didn't realise was that some clever turkey had replace d the feed-line with plastic water pipe - an inch of water pipe is not considered a good ground, so he added a new earth stake along with the ELCB.

I refrained from mentioning the smoothing capacitors, as that game is not for inexperienced amateurs.