Detecting if fan is on

I have a Homewerks bathroom fan that is remote controlled (not smart at all) but I can control it with the bond bridge.

I was wondering if there is any way to detect if the fan is running already? I’m trying to create an automation that turns the fan on if humidity is above X and it works but the problem is, if the fan is already on, since there is no difference in the remote code for on or off, the fan just shuts off. Other thsn detecting power draw, I don’t know how else. I don’t have enough room in the light switch box to fit a power monitor.

I’m thinking maybe vibration?