I just bought a 1994 Fleetwood Brougham. It has a few problems that I need help solving.

One is the trunk leaks and we think it is the glass. The car has a vinyl top and just wondering if this is a common happening. The leak is in the right hand top corner of the trunk. Got in the trunk, closed the lid and had someone pour water over the trunk and a lot poured in.

Second issue is periodically when I hit a bump the interior light turns and stays on. If I hit the brake pedal, the light goes out, but when I let off the pedal it comes back on. Any suggestions?

Electrical issues are hard to track down. Sounds like there is a loose connection somewhere. I don't envy you with this issue.

As for the water leak issue, this is really very common from what I've read. In fact, my Brougham with vinyl top has the same problem in the same spot (as do all others, it seems to be exclusive to passenger side leaking in trunk).
I fixed mine by removing the trim piece at the bottom of the vinyl top that wraps around the backside of the top just below the rear windshield.
The trim piece is very thin and simply pulls straight off the car. There are small white clips that hold the trim piece on and can be very brittle. You may need to purchase some replacements when all is said and done.

The backside of the clips have a single tab that presses into place (if memory serves) into a hole in the body. These holes are what leaks I believe. If you fill the hole with silicone and then replace the clip it should seal it off.

I also added clear silicone in the right side body seams located in the trunk jamb. This was I originally thought the leak came from but now I am pretty sure it is the vinyl top clips (holes behind them) that allow water in.