How much of a risk is it not earthing a ceiling light?

[fairplay]

This a very, very old thread but the one of no earthing in lighting circuits is a common one and always very relevant. Hopefully the OP did something sensible and is still alive. There are a couple of points here though that the professionals don't always take into account. Not everybody earns electricians money so the glib "rewire your house" suggestion is not always an option. If you don't have the money you simply can't do it! Then there is the disruption and potentially wrecking your whole decor consideration. The good electricians can usually find a third way. Providing that the house wiring itself is sound he could have done what I have had to. Add earth to rooms where it is simple and cheap, when you can afford it, or when decorating. Then stick to plastic switches with plastic screws or screw covers. Use pendant lights and plastic fittings or class two double insulated light fittings. There are hundreds available nowadays including metal ones. Put a notice in your fuse box stating that the lighting circuit may not be earthed. This is safe and meets the current regulations.