Oscillating fans are on sale this time of year in the Midwest. I had been thinking about asking. So this thread starts to help:
A) How to securely connect a prop to a fan
B) If the air from the fan makes the prop clothes puff out
C) If the prop sounds like a fan or is the sound muffled by the prop clothes
D) If the motor burns out if the fan is removed
E) If people use the tall or short fans
I'm not sure the original question exactly had to do oscilating fans but it sounds like that same type of motion.
Here's a link where they had a motor burn out and this shows how they solved their problem.
I also like the pose on the grim reaper for an oscillating motion 1 minute into this video
that someone linked to elsewhere.