i have heard they hide in the door panels just behind the speaker and wait till you close the door then they jump out and mess with all your stuff !
a Cat should be able to catch the little buggers
on another note.....
do you know what fuse number this particular lamp that offends is drawing its electrons from ?
that would help me help you.
if you dont know... pull one fuse at a time till it ceases its foul function, then look on the legend and record the offending lamps fuse number...
relay this information to the crowd of onlookers prepared to assist and I am sure such answers will arrive in great enough numbers that your misery shall be avenged.