you might have paper or something sucked into the blower fan, i think some once here had envelopes fall out the back of the glove box and got into the fan.
pop the glove box and check behind it, and if you remove the cowl under the windshield wipers on the pass side you can see right into the squirrel cage. same instructions as if to fix the water on pass side floor when it rains. if you want to see what it in tails, just search.