Vent Selector switch is stuck on panel -- will not allow to move

What is your question?

When I attempt to choose another setting on the vent selector switch (i.e.: move from panel vents to defroster or floor board) it will spring back to the vent position. If it does catch at another position, a sucking noice can be heard. I am assuming it is a vacuum leak, but am questioning if it is the selector switch itself.