Factory Accessory relay

Yep, I have a few spares as both my cars are wired with it. Any high end mopar or one with illuminated ignition key up to 1998 will have one plugged into the under dash fuse box. Thats where I got mine from.

It's called a time delay relay. As soon as you open the door the dome light power switches it on. That provides power to the contacts. These turn the ignition switch illumination light on. The contacts stay closed keeping the keyhole light lit, until it gets hot enough to kick the contacts open. That's when the light goes out.