Well just for instance the one in my ‘06 Cobalt sedan has been acting up since I got it. Driver side window switch had quit working at some point. I had messed with it and got it working again. Now the rear ones don’t work. I accidentally hit the one for the rear window, magically it started working one night in recent weeks. It’s quit again and luckily I put the window up as soon as I rolled it down. Switch panel is bad.
A number of things can cause it. Moisture, like when it’s humid. Spraying cleaner on it while cleaning the interior. I did this when using fabric cleaner and I know that’s what ruined my switch. Also screwed up my mirror switch. I didn’t think much of it at first, but the cleaner over sprayed on the switches and got in them. At some point I’ll grab one at the junkyard. They are cheap and easy as pie to replace.
There is really only one way to make sure it’s the switch. And that would be testing it out. Best way is to check for power at the window motor. Unplugging the motor and testing for power when the switch is operated is what it would take. I doubt both window motors would go out at the same time. They usually get slow and lazy before going bad, not always though. Usually will start to lag going down or up when they’re getting ready to take a dump. Switches are usually more sudden.