Replacing an old plastic light fitting and the OH has picked up a fancy metal, non double insulated light fitting. This obviously has three wires, live neutral and earth.
The existing ceiling wiring however consists of two neutrals (black) and one live (red) being of 1960’s vintage.
Solid walls and concrete ceiling so this wiring is run through metal conduit as far as I know. There is a round metal fitting on the ceiling currently sitting proud by maybe 1cm of the plaster finish and I can see the nuts that will presumably hold the conduit rods.
Can this metal round fitting be used as a suitable earth for the light fitting or is it much easier to go double insulated?
I have a multimeter and I believe you can check for earth if required.
Circuit breaker renewed in the past two years if that matters.
Thanks in advance.