The door jam switches are built into the door latches on that car. They have a history of having sticking problems. here's a procedure that usually works very well.
Get a can of spray lube like WD40 or something like it and has a straw on the nozzel. Spray it generously up into the latch mechanism. Now open and close the door numerous times to work it in. Repeat this process several times. Since you don't really know which door is causing the problem, you should do all of them. It's usually caused by the most frequently used door but it's not gauranteed to be that one.