Cargo lamp missing, shorting out

[Nomad7801]

I have an '88 Mitsubishi Mighty Max. The cargo light is missing, leaving 2 holes in the top of the cab. When it rains water is getting in and blowing the fuse for interior lights. I have plugged the holes but am wondering if I could wire another light source to the wires. There are 2 grey wires. Both wires are positive connections. How should I wire these lights that have positive and negative? Is that for a light like the cabin light? Can I run 2 lights off these and ground them?

[Nomad7801]

How do I bypass the cargo lamp to get the interior light to work?

[Nomad7801]

209262092720928

[Giovanni89]

my guess is that 1 wire is always hot and controlled by the switch on the light. The second wire is probably hot when you have the door open; switch near the rocker panel. The switch on the light controls what gets grounded (probably through the mounting screw). I don't have a wiring diagram any more, but i would bet that is the way it is wired.
To bypass it you can can just cap the wires.

[Nomad7801]

Thanks, it's still shorting out on me I'm thinking its a bad ground wire somewhere.