My garage wall switch doesn't light up or open/close my garage door anymore. My garage remote works perfectly fine, and I know the wires are fine too. I've unscrewed the button to take a look at it. There's a red wire connected to the top screw, and a black wire connected to the bottom screw but there's a yellow and green wire that doesn't seem to be connected to anything. Is this normal? Shouldn't they all be connected to something? Or is the button itself in need of replacement?