Its just part of the interior lite delay/timer.
While on the subject, I wanted to warn you about something else there...
the door panel lite switch.
The white plastic on the door panel is a switch that turns on the door lite. If thats accidentally turned on, you will probably not notice exiting the car since those lites normally come on when the door opens.
This can drain a battery when parked for several days. To check, just wait until the timer turns out the other inside lites then if a door is still lit, push the switch. Make sure the headlite knob is not turned to "dome" as well. The mirror map lite does 90% of what I need to see inside the cabin at night. You should have 2 bulbs there...one dim for the ashtray, the map lite thats on a switch.
These door switches are the cheapest all plastic switches I've ever seen and tend to break when used repeatedly, so if they work, be gentle with them. If they don;t work, ....thats why. Cheap switch. I repaired mine. I do not know where to get replacements or if they were ever available. A different type of push button switch (micro-switch or limit switch) would work better if it came down to replacing the switch.