It would be useful if you 1) turned off the breaker that controls the switch. 2) Use a Volt Meter to 'test' the wires BEFORE you go poking around in there. (From the sounds of it, this is a little 'over your head' if you know what I mean.) 3) After shutting off the power and testing the line (try at 12V first, then 120v second), either 'maneuver' the switch so you can read the back of it, or unscrew a wire or 2 so you CAN read the back.
BEFORE you unscrew anything note 2 things. 1) What lead each and every wire attaches to the swith, and 2) the 'direction' of the loop at the wire's end. Draw a picture if you must and label each wire with masking tape, and number each tab of tape.
When you're finally able to read the back of the switch, write down the info. It should tell you Volt info among other things. Post back with that info and with the wiring info too. (We can't see it from here.)
As an aside, for your benefit in the future and for the benefit of others that might be reading this Post for 'info', be sure your Home Inspector is an ASHI-Approved Home Inspector. These days, ANYONE can take a home-learned course and call themselves a Home Inspector. I would be that an ASHI Inspector would have gotten his Volt Meter to 'test' the line to tell you what you had FOR SURE. AND, he would know if what you had for a switch could be 'substituted out' for a 120v switch, or vice-versa. Right now, I say DON'T do anything because you can't do that. Understand, wire loads vary and switches of VARIOUS types are made to match them. You don't, blindly, go switching 'things' out ESPECIALLY when it comes to electricity. What you can't see CAN hurt you.
Give us more details and we'll see if we can help you. My best to ya and hope this helps.