My boss has a 98 ranger 4x4 where can I find the door switch, I know they are magnetic, the door ajar light stays on.

 

Most try WD-40 first and that seems to fix it.
It will probably be a dealer item, I looked at LMC and they don't list it in the door parts as available.

LMC link here: Ford Truck Parts and Truck Accessories from LMCTruck.com

They usually have any ford truck part, and pricing is good.

 

its in the latch. $40 from ford. if i remember correctly its one phillips screw then turn the switch counterclockwise it pulls out. i removed the whole latch to change mine which was a PITA try removing it with the latch in the vehicle first.