OP
rattlehead85
Forget about the RCD anyway. First up you need to determine if you have installed a low voltage light 230v or an Extra low voltage light 12v. Do you really have an earth connection or not.
Secondly with insulation resistance results like you claim to have i would definately be looking further into the circuit with regards to its condition and suitability to be adding a light and fan onto it in the first place.
Secondly with insulation resistance results like you claim to have i would definately be looking further into the circuit with regards to its condition and suitability to be adding a light and fan onto it in the first place.