Brand new to the forum and first post

So, the dome lights are stuck on, but very dim along with dim taillights remaining stuck on. I imagine that is what is supposed to happen when I open the back hatch gate, ya know? Just a dim dome light and dim taillights to help me see. But they stay on until I OPEN the hatch door or use the brakes. I don't get it. I just bought this 2000 Jeep Cherokee Classic and am new to it so I'm learning. Last night I had to leave the hatch gate completely open so the lights would go off and not drain the battery. It's weird. It just started happening. Completely backward. Open the gate, they go off. Close the gate, they come on.

Any ideas?

Thanks
TommyB