What is the white smoke coming from the air conditioner vent in a 2002 Ford?

If it doesn't smell like smoke it could be comdensation off the evaporator core. You might have a clogged evap. case drain. If it is left unchecked it will start to smell moldy. If it is smoke, it usually be gray or black due to melting wires(also stink), afaulty blower bearings( would make noise).