The main cause of a ceiling fan wobbling is due to the mialignment of the fan’s blades. Just like a car tyre that is out of balance which causes the tyres to wobble when it reaches a certain speed, the celing fan also wobbles almost with silimlar reasons.
The fan blades can go out of alignment due to 2 common reasons. The main culprit is human ignorance. When cleaning the fan blads, care must be taken not to bend the blades. Though the blades itself don’t bend easily, when mopping the blades, one should not put too much pressure on any one of the fan blades. The blades are designed and aligned in such a way that it cuts thriugh the air in such a way that air is circulated.
If you look at thye blades, you will notice that the blades have one side bent so it can slice through the air soomthly. all 3 blades have that same angle and if any one blade is out of that angle, it will not balace properly. One blade will be cutting more air then the other 2 thus causing the fan to wobble.
Once this happens, there isn’t much you can do to align it back other than to replace the blades. Some people have said that it is possible to detect he fault and align it back, but from my experience, it doesn’t work.
Another cause is due to waer and tear. After many years of use, the blades rust, causing the weights of the blades to be different. In that case, I think it is high time the fan gets replaced as you would have used the fan for years for the rust to eat through.