To clarify; I have not yet sprayed anything into the dial mechanism.
This used to be a light switch, but my son kept leaving it on. So I swapped it out for one of these dials about 2 years ago. Now it seems to be getting stuck around the 10-min mark and being left on all day.
I’d prefer not to replace this dial again; the house is old and the wiring in that receptacle was already pretty hard to work with. But I mean I’m not going to burn my house down in an effort to save myself 10 minutes and $10.
Is it safe to use a silicone based spray on it?
I would not use silicone spray, personally. It might be perfectly fine, but I’ve never had it recommended to me for that purpose.
What I have been told to use, and have used regularly for a few years is CRC contact cleaner. You can find it online or in stores like harbor freight or just about any hardware store. It’s supposed to clean and lubricate electrical contacts, and works really well.
Contact cleaner was my first thought too, I’ve used it successfully to unstick potentiometers like volume knobs.
In this case, depending on the source of the failure, neither that nor the silicone spray might be sufficient. There’s probably a spring in there which could be stuck or partially rusted from moisture (in which case a selective dose of WD-40 would help, followed by some form of lubrication). I’d try to take the cover off and take look at the mechanism first.
I’ve never done this so take what I say with a grain of salt. If you are going to try silicone spray, I would cut power to the switch first. Those cans have flammable propellants in then.
Once sprayed on it should be fine though, and since it’s indoor the silicone won’t gunk up much, though I personally prefer to use a dry lubricant to prevent dirt/dust from building up. The same company makes a dry lube can.
Some dry lubes (graphite) are electrically conductive. So are some wet ones for that matter. Something to watch out for.