>>/44897/
Asked pal. He says back in the day it was the standard that they tied the Ground and the Null together in a box (most likely where the circuit breakers/fuses are) but standards changed and now one of those are counted as Line too (he said which one I forget, it doesn't matter to our point, I think it was the Null however), and they provide electricity in a different way (said something about inverters and such).
If the tubing gets wet, the moisture in the form of vapor can go through the whole system, also causes corrosion. Somewhere the damp closes the circuit for you. You should check each connection box to see if the Ground and Null are connected together. If you are lucky, it's just that one distributor box at the room where you have this problem (but most likely this will be at the fuses at the very end of the circuit, as stated above).
Btw you might experience if there were no Ground at certain places like the tap or washing machine (they could electrocute).
The solution is to take the Ground and Null apart. Problem is you won't have ground anymore. If it is only at the room and not the fuse box, it isn't that big of an issue.
Maybe you can ask the electric company to make a new Ground for you.
However the whole issue is bad for the wires they are deteriorating. Real solution would be to rewire the whole thing...
Additional information: try a normal bulb instead of the led. That won't light - but this won't solve anything.