Where is the interior light relay on a 1998 Cadillac sedan deville?

The 1998 Cadillac DeVille's interior light relay isn't a standalone component like in some older cars. The interior lighting system is controlled by the Body Control Module (BCM). There's no individual relay dedicated solely to the interior lights. Any issues with the interior lights are more likely to stem from a problem with the BCM, a faulty switch, wiring, or even a blown bulb.