Heat generated from rear wiper motor

Hi all, this is my first post on here and my 110 is my first Landy... so a bit wet behind the ears!

My '87 110's rear wiper is not working, and wasn't when I got it.
The truck has been coverted from a van into a camper (of sorts). On a camping trip one night, and after having the ignition in the 'on' position so I could listen to the stereo for around an hour, I happened to touch the metal wiper motor cover and it was fairly hot.

The wiper knob I think was in the 'off' position (turned anti-clockwise).
I've seen from a couple of older threads saying that these motors don't always perish, but that the wiring frays.
Any thoughts?

Don't fancy a potential fire risk, especially if I'm asleep in it at the time!

Discon it while you sleep. Job sorted. Also fix it after winter, you'll be wanting the warmth

or.. you can take it apart and check the magnets haven't fallen off and that it isn't all rusty.

Mmm... liking the idea of free heat... sounds like I'll be stripping it then!