issues with door trigger perhaps or jamb?

Hi saxproff27...... Looks like i have the same problem. This is a '98 Expedition 4WD 5.4 engine so we might have the same situation.I just began the repair process and i will post the running story as the repair proceeds. Maybe you can learn from my mistakes.With this vehicle the interior lights and running board lights stay on even with the door shut and the engine running.If you shut it off eventually the lights will go off. In about an hour or so.Step 1 - like you i began by poking about on the internet. Seems that these expeditions are well known for this problem. The door ajar switch is located on the bottom of the door latches, and get sticky over time.Step 2 - lubricate, with wd40 or equivalent, from outside, all door latches. So i hosed them down good... ^_^... no luck at all, same problem.Step 3 - pull the relay and see if swapping another from the fuse box (as there are 2 exactly the same) might help. No luck eitherFor location of the relay see here: http://www.analogstereo.com/bx.phpSee pages 131 and 133.Step 4 - pull drivers side door panel and completely remove the latch and door ajar switch. Tested the switch with an Ohm meter and all tested good.Step 5 - pulled the headlight switch and unplugged it (since it has the interior light switch on it) even with the headlight switch and drivers door switch out... the interior lights and running board lights remain ON.This is where i am right now. As i said before, as i test and continue the process, i will keep a running post going and maybe you can follow what i did and save yourself some failed test steps. I'm heading outside now to continue working.Wish me luck   ^_^Wrenchcat

Check the switch in the hatch.  I do not know if it is in the window latch or the door latch.  But there seems to be problems with one of them.

OK...its fixed.. I pulled the passenger door panel and unplugged the door ajar senson..same problem.    Pulled both back door panels, unplugged the door ajar sensors.. same problem. Finally, the tailgate.. I noticed that the tailgate latch was very rusty...hmmm. Pulled the tailgate panel off and unplugged the tailgate ajar sensor and the interior light and running board lights all went off. ^_^ So i went to the parts store and $10.84 cents later...all is fixed and working normally. I sure hope my little escapade helps you out. If you need any other info about the job (such as how to get the door panels off) just let me know. It's all very fresh in my mind. Or i could even post pictures if you need. To *i am an idiot* (which obvioously you're not) you were very much correct in having me check the tailgate. Thanks very kindly.    Other than that ... My best to you all. Warmly. Wrenchcat

Glad you got it figured out.