Looks like a tank heater for one of your holding tanks. They are usually glued to the bottom of the tank. Does it have a couple of wires attached or a place where the wires looked like they were connected?
Lee & Kathy
2017 Starcraft Autumn Ridge 266RKS (with Jayco P/N's)
2007 Toyota Tundra with 140k Trouble Free Miles
Clean the bottom of the holding tank and put the pad back on. Get some Eternabond tape, and apply the tape around the edges of the tank heater pad. That should solve your problem.
Make sure you prep the area where the Eternabond is going. Acetone or mineral spirits should do. If you're not familiar w/ working w/ Eternabond, search or forum; many have posted. Quick hits: Don't stretch it, and apply it w/ a roller.
__________________ 2022 Winnebago Minnie Winnie 26T Experience is what you get when you didn't get what you wanted.