I have an older house and am not sure about replacing a switch. I removed my old switch and found out that there are only 2 wires, White and Black. I got a Lutron PD-8WCL and see that it has 3 wires. I tried connecting the Green from the Lutron to the Black wire from the wall and the White from the wall to one of the Black on the Lutron but no luck. Any help would be greatly appreciated..