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.