falcon16 said:
You've kind of answered your own question. Although the circuit protective conductor ('earth') of the lighting circuit should, ideally, be supplementary bonded to exposed conductive parts in the zones you'd be wrong to do this at a Class II (double insulated) accessory. If you can, you should make the bonding connection at the light position and modern ceiling roses have an extra-large earth terminal for this very purpose. (Of course, if you've replaced the rose with a flashy new bathroom light you'll find the designers have no idea that this might be an issue!)
