You probably need a relay rather than a 'smart light switch'. This is because the light switches frequently rely on leakage through the lamp to power the electronics in the switch. With a fan motor, this might not work as intended. You would also risk some damage in using a dimmer to control the motor.
The key difference with a smart relay is that the switching element takes feed and return power directly, providing independent terminals for the load. They can use either mechanical relay or electronic ones - just make sure it is suitably rated for an inductive load.
As an example, LW821. You would typically wire this in the ceiling void, and then have the challenge of how to manage the switch - so you might replace the switch with a LW-RF transmitter (confusingly described as a wire free switch) - rather than trying to come up with a 3-way control.
You will not be able to mount the relay at the switch location because there is no 'common return/neutral' in a normal switch location. Effectively, you need to install a switched spur (and this most likely means some places require an electrician to certify the work).
