My wife's 2002 Taurus SEL has been exhibiting strange behaviour lately. Driving down the road, the doors unlock and lock, and the door ajar light flashes. When parkedwith the doors locked, the interior lights come on by themselves, and if locked with the key fob (arming the alarm) the alarm goes off randomly. I tried soaking the latches (and switches) with WD40 with no effect. I have narrowed it down to the left front door circuit triggering the alarm and lights. I took the door apart this afternoon and removed the switch - checking it for function. The switch tested OK so I put it back in. There were some iron filings on the switch, which I removed by washing with WD40 and blowing with compressed air, suspecting they could POSSIBLY be able to cause a short. There is no difference.
It appears it may be a GEM problem - the generic electronics module that controls just about all the "bodily functions" of the car, Not a cheap part - - - - and one that requires reprogramming by the dealer or someone with the specific tool required to save the data off the old one and transfer it to the new one . . . . . . .
Looks like it may have to go to the dealer for the first time in 3 years at 97000km.