Hi,

I have a light fitting hanging precariously down from the roof middle of bathroom, where the worn earth wire is connected to some sort of steel collar, presumably earth. Other wires are fine.

I want to replace the fitting. Questions;

1. what new wire do I need to buy, to act as earth
2. are there any regs that apply to fitting a new light, esp. as I am renting the flat
3. what are earthing arrgts likely to be i.e. what is this steel collar in the ceiling
4. the wiring is from the 60's- what's the colour coding and does it matter if I connect + /- wrong way around?

Most grateful
Cheers:D

Sounds like you are across the pond. What are the colors you have?
Here green or bare is ground. White Neutral, (gray sometimes),
Red and Black are usually hot for single phase(Residential)Most other colors can be hot,
Except white, green, bare, gray. Blues, browns, purples, and others, commonly used for travellers, or switch legs.
Yellow common color for switchleg, or to a light.
Orange common color for switchleg or to a fan.
Can use other colors for light and fan.
Take Care.