Hi all, I am working on an ex-bathroom (no longer used as a bathroom i.e. no water!) and want to swap the pull switch with a wall switch. I have removed the pull mechanism and put the three wires (red, black, earth)into a junction box in the loft space above. I have then added a length of new 1.0mm twin and earth to the junction box and wired this to the new 1 gang metal plate wall switch. This tripped the rcd. I have strapped the metal plate to the metal back box so I cannot understand why this is tripping. Any replies would be greatly appreciated.