I think I've only had one bad switch on any gun I've ever owned(old timmy) and I broke that one due to my own stupidity. I don't remember exactly but most of those switches are rated in the millions of clicks so you're pretty safe. There's always the possibility one can get a dud I suppose. Or if you were to let it rust there could be problems. Other than that, it's pretty much a non issue.
Etek 3LT grey/black f/s
Valken Proton greyish/black f/s
68 4500 PE stubby, LP output f/s
68 4500 AIR tank(no reg) f/s
Creed/demon eyes f/s