1999 Dodge Stratus - Door Ajar Indicator - Car Possessed!

I have a 1999 Dodge Stratus with approximately 130,000 miles on it.

The other day, I noticed the interior light was on, even though the car was closed up and locked. I got in, shut the door, and the light remained on. When I started the car and put it in gear, I realized why: the "door" indicator flashed on my dash. I opened the door and shut it again, but the light didn't go away.

I made sure every door was shut tightly and then started driving. As I drove, it kept shutting the "door" light on and off, as if the door was shut and then not shut, shut and then not shut. It was quite irritating, as it makes that "ding!" To warn you every time.

Then the locks went crazy. The Stratus is programmed to lock the doors when you shift into second gear. As it couldn't decide if my door was open or shut, it continued to lock and then unlock the doors every two seconds. Between the constant dinging and the locks going crazy, my car felt possessed. (The locks themselves never popped up; rather, I just heard them locking into place.)

I noticed that the interior light will stay on if I lightly press against the door and then pops off if I let off. Slight bumps in the road must be causing the freak-out. I tried resting my leg against the door while driving today, but the car remains "possessed".

This started when I got to work the other day and tried to hit the auto-lock button while my keys were in the ignition. It wouldn't let me lock the doors, and I thought, "What a good safety feature!" Now I'm wondering if I messed something up.

I've checked the hinges, door latch, etc, but nothing seems amiss from what I can tell.

Please help!