Checking air conditioner. How to avoid stings from wasps ?

My smaller bedroom a/c made a terrible " shred up the roof " sound. I dont mean it blows hot air, or the compressor makes noise. I had to turn it off quick !! I need that a/c a.s.a.p and looked to Youtube. Somebody had a video, got up and checked his shroud and a/c. It had a hornets nest in the fan and it put it out of balance, thus the horrible sound he said, im hoping that is all i have to do, and blow out the fins with a compressor. I really want to avoid getting a new a/c if i didnt have to. Please tell me how to avoid the wasp if confronted. Or what to do ahead of time ---? Please advise.