My Sami had this intermittent tail light problem. Sometimes they'd all work, other times, one tail light out, other time a different brake light was out. My 17 year boy drives it to school, so it's got to be in good shape. If there's one thing I learned from being 17 once, it's that a 17yr old doesn't need any more reasons (other than being 17) to be pulled over by the local police.
Samurai factory tail light housings don't appear to be super-high quality when they were new. 25 years later, the contacts are tarnished and corroded, like any car of that age who has lived a tough life. It came with a set of spare lights, tried those, they were worse.
I messed around with dielectric grease, which keeps things from corroding, but it didn't fix the problem. Then I remembered this copper-based electrical contact paste I'd purchased from Eastwood about 15 years ago. I fished it out of my toolbox, and dabbed a little on each bulb solder 'tit', and a little around the steel housing that grounds the bulbs to their sockets.
Problem fixed!
Just thought I'd pass it along.