I have the same problem, but once upon a time (before I bought my 96 EX), somebody stole the radio out of the car, and I'm guessing they busted a wire up in the dash somewhere.
When I was trying to track down the problem though, I found out that the dome light was wired into the passenger side door switch. See if you can pull out that door switch, look to see what color wire it is, and then pull out the back seat and trace the wire as far as you can. My wire runs from the passenger side under the back seat to the driver side, then up from there to the fuse box. I'm not sure exactly where it leads up to the dome light, and I've found that the wiring diagrams themselves sometimes aren't much help (or maybe I just can't read them).
Maybe that will at least give you a starting point.