93 Blazer pushbutton 4x4 button,no lights,no 4x4 engagment when pressed

Hello........i just bought a 93 blazer 4x4 and the push button for the 4x4 worked intermitantly and now doesnt light up or engage the 4x4 in any mode.
Has anyone heard of this before.....could the switch itself be bad or the part ot connects to behind the button be broken....dont know....:(
can someone please give me some help...........
thank you