dirty white boy

Wife's trailblazer selector switch is dead. No lights, no changing to 4WD.
I noticed this a couple of days ago when we were actually in the truck at
the same time. About 6 months ago, we had the transfer case module replaced
because it would intermittantly change the lights indicating what mode it
was in, but not actually change the transfer case. Right now it is in 2HI
and will not change, which is better than 4LO I guess. I have checked the
fuse under the hood and the fuse under the rear seat and both are good. Any
other things I might look at?