Hi , I am looking for some advice , I have recently moved house and in the living room there is a 3 gang dimmer switch controlling 3 wall lights. there were only 2 lights fitted and the 3rd one was just wires. I have changed the two with n9 problems but I am having difficulty with the 3rd. I have wired it up but it is constantly on. I have 2 cables coming out of the wall, 1 is 2 brown and 1 earth; which is the switch wire.the other cable is 1 red 1 black and 1 earth. I have fixed the switch live to the light fitting (brown) and the black to the blue on the fitting . I joined the red to the other brown but the light stays on. the other lights work fine. is my actual switch wiring the problem ? can someone give me some advice ?