The back plate of the light is metal - the instructions that came with says it doesn't have earth as it's double insulated (theres 2 plastics casings that go over the bit where the terminals are)
Apologies for posting what seems to be a fairly commonly asked question but all the replies to the threads I saw say to look at the projects but the projects I found didn't help much... I'm replacing a wall light and am confused as to which wires I need to connect to which terminals on the fitting. ...