Fuse that turns on when car is off

[vthreee]

By any chance, does anyone know a fuse that goes on when the car is off or not in use?

I was hoping to hook up a light that would turn on after I park the car.

 

[jmaddr]

I don’t have a direct answer for you. Hopefully you can find such a wire.
If not, a very simple and very cheap “normally closed” relay could be added to a standard 12V switched and a constant 12V source to get what you need.