Melody,

It depends on where you are. If the air outside has a higher absolute
humidity than the air inside, the fan will make it worse. To determine
that you need a sling psychrometer and a psychrometric chart. In the
humid south, what you are suggesting would be a very bad idea, because
the air you blow out creates a vacuum inside the house. Then humid
outside air is sucked in to the house to replace the missing air and
the humidity goes up!

Stretch