I got our "door ajar" switches at "The Mopar Shop."
http://www.themoparshop.com/shop/They have them, but they're not in their latest online catalog. To see them on his site, click on the Mopar online info pages and then click on old catalog.
When I got them, I thought they were too long, but Ed, the owner, explained that you screw them in and then close the door, and the brass collar is pushed back to the right length.