A while ago I wanted to put up some shelving in my flat, I ensured that I bought an electric/metal detector for safety purposes before undertaking the work but unfortunately I get detection of current in all the plasterboard walls/ceilings in my property. I contacted my landlord who sent an electician, he assured me that my detector was too sensitive and was only picking up static. He was quite shocked when he tested for current and found more than 14 volts flowing through them. He could not work out where it came from, but in all honesty he didn't try very hard. He told me he was going to speak to others he worked with... And that was the last I heard from him, I've repeatedly contacted landlord and got the same result every time! I spoke to them and told them I was v.worried about this, their answer was that I should get someone in and they'll compensate me! This isn't possible as I'm on a low budget and getting money out of them is impossible! The current does not trip breakers and disappears when the lighting circuit is switched off, light bulbs repeatedly blow and I require the second flourescent light in 9 months in my kitchen. The problem is repeatedly damaging T.Vs, digi boxes and anything with a laser or hard drive. Does anybody have any ideas as to the cause and a solution, any help would be greatly appreciated.
My apologies for the length of the post and thanks in advance.

Earthing is complex and to try and guide anyone through all the different earthing methods would take some time and also likely to miss out something.

Clearly you have limited knowledge as current is measured in amps not volts so there is a mistake some where.

The cable tester is quite a hit and miss unit except where using proper CAT tester with sender and receiver. They just show likely routes.

As to a bad earth damaging equipment that's unlikely. Items like a TV is normally double insulated and has no earth connection.

In the old days two way switching used two wires and an earth between the switches but this caused an induction loop and could produce mains hum in the newer solid state equipment. It was OK in days of the valve. This would also likely mean testers giving odd readings. Today we use three wires but although not ideal the old two wire system was not dangerous unless the lighting circuits were split.

Even if re-wired likely next door is the same so it will not help. I would think it would be hard to get anyone to alter the wiring. If I was faced with problem it would be just a case of disconnecting two way switches so stairs light switch would only work either at top or bottom of stairs not both.