Quite a few disposal call-outs turn out to be a two-minute fix, so it is worth trying before you ring anyone.
Start here
If it hums but will not turn, the motor is fine and something is jammed. Switch off the power at the wall, use the small hex key that came with the unit to free the flywheel underneath, then press the reset button on the bottom. If it is silent, the reset alone often does it.
Rentals see the worst of it
Guests put things down a disposal that no owner would. Shells from a seafood dinner are a genuine island specialty and they are hard on the unit. A note in the house information really does reduce call-outs.
Salt air reaches the underside
The housing corrodes from the outside here as well as the inside. If water is coming from the body of the unit rather than the connections, it has rusted through and cannot be repaired.
What it does not handle
Cooking oil and fat, which set further along the pipe and combine with sand already in the line. That is the usual reason a beach house kitchen drain starts blocking.