Fan + Light Controller?

Most people do use a double gang switch. It’s just simpler.

However, there are two other alternatives. The first is a dual relay switch that fits inside a single gang box. These are popular for bathrooms where one button is the light and the other is the light. The problem is these are typically just on/off for the fan, not variable speed control. Fine for baths, but most people like low/medium/high for other rooms. But if just on/off would work, see:

The other alternative if the fixture allows it is to put the fan on one of the wall switches and control the light with an Aeon micro placed inside the light fixture.

Do not connect the micro to the fan motor! Only to the light itself. See: