It's Homeless Harry. I had the same problem - a few mechanics checked it out, tried to "fix" the problem - no solution. Given I leave my Jeep open, I suspect that Homeless Harry sleeps in my Jeep at night - and given he's afraid of the dark, leaves the door ajar - the interior light serving to keep him safe from the bogeyman.
Anyway, my main mechanic is a no-nonsense kinda guy - so he offered me two solutions - both involving a battery disconnect. You can buy a cheap one that attaches to the battery (the route I took), or they can install it inside the Jeep.
Luckily for me, Homeless Harry is a crackhead and can't figure out how to re-connect the battery, so he's moved on to another Jeep. Possibly yours?
At any rate, it works. No clue what's causing it, and I kinda don't care anymore. But my no-nonsense mechanic did relate that it wasn't fouling anything else up. Best of luck.