i have 2 lights in my living room 1 at each end of the room and 2 light switches both turn on and off by by the same switch can I change 1 switch for a dimmer switch to control both lights and how to wire it correctly switch 2 is earthed at the back plate switch 1 is not earthed at the back plate the dimmer I want to install is a chrome plated dimmer switch thanks for any help on this