Light Switch Wiring Doubt?

I need help!! or advise... I am changing my room's light switch to a more modern one... I read articles online and found it very simple to do, as always, turning the circuit breaker off as FIRST THING. But my question is the following: The breaker feeds 2 rooms, in one of them only the outlets, and on the other one (mine), outlets AND the switch, I have no idea what gauge is it either 12 or 14, the breaker is 20 AMP. The Light Switch says %26quot;only use #14 wire, I tighetn both screws the light seems to work perfect, but...what if the wires are 12 gauges? what could happened, should I take the old switch back, or no big deal... THANK YOU!!!!
Light Switch Wiring Doubt?
I have no idea where the dictum about using only 14 gauge wire came from -- it is total nonsense. Any switch will work perfectly well with 12 gauge wire as long as you use screw connections. (Push-in type connections are recommended to be used with 14 gauge wire only, as such are less safe if used with 12-gauge, which implies a 20-amp circuit.) If you connected the same two wires to the new switch as were attached to the old one, you're done and it's time for a beer.
Light Switch Wiring Doubt?
awg 12 is a heavier (capable of carrying more current) than is awg 14. Thats all as far as the numbers go. If you were able to get good connections with awg 12 no big deal. I doubt that awg 12 was used with a 20 amp breaker anyway.
Your fine. #12 wire gauge is good for 20A, and the #14 is rated at 15A. The switch is fine. You said that you had tightened the wires, and that's all it takes. No big deal.
14 gauge is in reference to the %26quot;push lock holes %26quot; on the back of the switch. By using the screws it will not matter.