The worn out switch is a Cooper. I ordered a Levitron, which I understand is the same company, as in Peerless faucets are same company as Delta faucets. Why did I order, because it's a 20 amp stack switch (two switches). Why 20 amp for a light, because the other switch on this stack handles a bathroom heater that draws 15 amps and occasionally kicks the 15 amp breaker. It had a 20 amp breaker and is wired #12 wire, but I found melted insulation on the wire by the old switch I replaced in 2002, so figured the 15 amp breaker was a better deal for safety. It's overkill and the 20 amp switch is $20, but I want to be anally safe.
Oh and this was a professional electrical supply place, Home Depot does not carry this switch. I mentioned the worn out condition of the switch and my concern for possible fire hazard and the counter guy said it won't start a fire as it will kick the breaker, that's why there is a breaker. I said, but what if it gets in a position of contact that is a poor contact, won't that create resistance and generate heat. He again said, no it's either on or off, it doesn't work that way. Though he talked with an air of knowing what he was talking about, I think he is misinformed. Yeah, if it gets a poor contact and generates resistance, it will kick the breaker, but not until it reaches 15 amps and I can toast a lot of loaves of bread with a high resistance toaster and never kick a breaker, so he must be wrong. And the fact that wires in there before 2002 had melted insulation also shows the fire hazard situation. In theory, it will kick the breaker, but in practice it may not get to the 15 amps needed to kick it.
I could stick two naile in an outlet, shorting it with my body and the electrical system will think I am a toaster and fry my keester, not kick the breaker or if the breaker kicks it will be after significant damage is done. Even a GFCI would not help if you stick two nails in the outlet, else GFCIs would kick on toasters.
I think I know a little bit about household electricity. It's electronics where I plead total ignorance and bafflement.
Whew!