I live in Germany and I have just moved into a new apartment and started to change the light fixtures, but I ran into confusion. Wires coming out of the ceiling are - two black & two white (no earth), and no grounded mounting plate - just a screw into the celling. Also, none of the wires were tied together.
The light fixture I wanted to remove had one of the black live wires attached to the live terminal of the fixture (cool), one of the white neutrals connected to the neutral terminal(cool), and then... the 2nd white neutral was connected to the light fixtures Earth!? I plan to replace it with a fixture that also requires earthing.
I believe that at the main power source (municipal), Earth and Neutral are tied together, but is this common practice? Should I connect the second neutral to the earth, or should I rather not 'ground' my light fixture?
(btw: the light is controlled by a dimmer)