Strange happenings with interior lights and dingy thing
 

My GF's 96 bonnie SE, has some wierd things goin on with the interior lights, basically they come on when you get in car, and remain on the entire time while driving, and then after shutting off and leaving car they stay on for a good 5min with key out of ignition...
also the headlights remain on now too.....
another annoying thing that happens is on hard braking, and sometimes at idle the dingy thing will go off, like the reminder to take your key out before leaving the car dingy i believe...while its happening at idle, if u give it a little bit of gas it gets quiet...
is this all related to the door ajar sensor thing? and if so where is this at? is it inside the door panel?
Thanks for anyone who took the time to read this...!

From what I've seen on this board, at least half of the type of problems of the type you're describing can be cured by thoroughly cleaning or replacing the battery cables.

It sounds nuts, but it works. As to the dinger going off upon hard deceleration-checked your oil level lately?