I would think if the electric fan vibrates it has lost a blade or balancing weight. Usually, electric fans are quiet and pretty much vibration free.
1949 F-4 Built to drive--script bed.
1956 F350 Stock rebuilt script bed
2007 F150 SC. Driven once in a while. 2015 Escape SE EB 1.6 Wife's ride
If there’s one thing that the government is highly skilled at, it is creating excessive amounts of bureaucracy and extra layers of red tape for people to wade through.