i was replacing my two gang switch with a new one, my wife took off the old one so i didnt know which wire went where.i have two leads coming out off the wall one with two wires(red&black)and the second with three wires(red,black n one plain wire sheathed in black)ive tried wiring them up but i cant get both lights to work properly.the connections on the back of the switch are common at the top and 1 way 2way on the bottom for both switches please help