97' cadillac seville interior lights not working

If it's just one door, check the door switch.
If the lights do not work regardless of which door is opened, check the "INT LP" relay in the rear fuse block (under rear seat). Unfortunately, this relay is controlled by the Rear Integration Module (RIM) based on input signals from the doors etc. If the relay fuse and relay are ok, then you may have to replace the RIM - check the car error codes (DTCs) first to make sure.

Hello, there is also a fuse and relay box under the right side of the dashboard near the firewall (on most Caddys). Check there.
You stated you checked the fuses, but put a question mark at the end... do you KNOW they are all good? Some vehicles also control some items via relays mounted on the fuse box... check them also.

Check the door switches, they are the ones that turn the lights on when the door is opened, likely the drivers door courtesy light switch is defective.

Check your fuses. If you can't find a bad fuse, it could be a faulty solenoid that opens the door.

There should be a manual release in the trunk near the gas door.

Check fuse in fuse box labeled 'DOME'. A bad cigarette lighter is usually what makes the fuse blow to begin with.

Behind the rear seat cushion in the trunk

You could try checking the fuses to see if any are blown, if the fuses are all good then it's possible the door switch is bad or not making a connection from dirt or debris, the door switch is generally located insdie the door at the hinge or its a push button switch, when the door closes it pushes the switch in, the switch may also be jammed in keeping your lights from turning on.

Their is a fuse panel in the trunk in on the driver side on the back seat behind the carpet is the computer and fuse panel they will be labeled.

I had a similar leak problem with a Bonneville. We had to dry the car out thouroughly , and went to a self car wash to direct water pressure at seams and gaskets to see where fluid entered vehicle. You might have to remove some interior parts....door panel...back seat....you need to verify how much gets wet....ie....just the floor?. Ours was a bad gasket/ seal on the firewall ....water was dripping on the ECM. took a whole day of waiting after washing....then drips would start on the vehicle interior.
Hope that helps ....Good Luck !

Because that switch is broken and stuck in the recline mode.