2000 Durango Blows Smoke Out Of Vents

I have a 2000 Dodge Durango that blows smoke out of the A/C Vents from time to time. Any suggestions? Blower motor problems? Let me know. Thanks!

Actual smoke? Then yes, I'd suspect blower motor.
Or water vapor fog that looks like smoke? Then I'd suspect something like a windshield leak or a clogged condensate drain line.