Simple automation is your friend.
Trigger, light turns on for x minutes
Condition, between the hours of x & y
Action, turn the damn light off.

Personally, I would leave it in place, and call it out as a feature in listings / showings. For your showings they can join the guest network and see how good their reception is.

I had put in a camera system at my last house and left it up with a cheap monitor for the showings. Sure I could have repurposed it after my move, but it was a good opportunity to upgrade with a guaranteed buyer for the old stuff. (and at a much higher sale price than I could have gotten off of marketplace listings.)