4 WD indicator lit on a 2 WD-only 1996 Ram 2500?

[jefechingon]

I have a 1996 Ram 2500 with about 125k miles, V8, 5.2 L engine, and is a 2-WD model BUT the 4 WD indicator light lit up couple days ago.

To be clear, it doesn't have 4 WD capability - any suggestions on why the 4 WD indicator would light up?

Thanks in advance.