99 Nissan Altima GXE. 78K. great car. Not many complaints. Recently, the interior light's been flickering on and off. more specifically, it turns on with hard stops and flickers on bumps occasionally. The light on the dash for open door blinks along with it. I've checked all the doors and the trunk and they all appear to be closed tight (as far as I know). Is there a possibility that one of the door sensors is loose or malfunctioning? What's a good way to troubleshhot this? I think and hope this an easy fix that I can take care of.