1985 s10 blazer 4wd lights

While i am driving my blazer the 4wd low light comes on for no apparent reason.The Truck is not shifting into low it is just the light that is coming on.This happens at all different times whether I am doing 65 or 35.It does not stay on for very long but is a little bit annoying.Any ideas what could be causing this?

it sounds like you may have a short in your wiring somwhere...