I'm replacing an old 2-way switch with a new Cooper Combination Device. The switch powers a bathroom light/fan, 1 switch controls the light and the other the fan. Link sows original wiring configuration: yankandlimey.com/lightswitch.jpg
My wiring is old, only difference is 2 wires are thick, 2 are thin. When I rewire it kicks off fuses, it also begins to control other lights in the house but a fuse will inevitably be kicked off. At first it worked, but then it controlled the lights of the mirror in the bathroom and in the kitchen!
Do the 2 thick wires go to the black screws and the 2 thin to the brass? This new switch also has a 2 circuit feed with a break-off tab to activate. I assume this needs breaking ?
Any help would be greatly appreciated.