Jeep Repair: 4WD, electrical state, transfer case

Question
 When ever Im driving my Jeep beeps"service 4WD switch" do you know what means?/?

Answer
There's a switch on the transfer case that I beleive is going bad.  It's not going to force your vehicle in to 4wd because it's mechanically shifted kind of like a 5speed car.  But, the electrical state of the switch is changing ever so slightly causing the position states to change.  This component is located on the transfer case itself, between the front driveshaft and the transfer case itself.
Doug