Remember using a playing card and a cloths pin to make that sound on a bicycle wheel. Ahhhhh, those were the daysOnce I got the motor unplugged and lowered I found a dried up leaf stuck in the squirrel cage. Pulled it out, put the fan back in, and it is silent.
No, a squirrel cage is the generic name for the fan type used on our blower motors. The noise was from a leaf touching the blades.Thanks for the replies! A squirrel was building a nest!