Garbage disposals take lots of abuse. Most of the time, they handle it just fine. But every now and then, something gets stuck, whether it's food or part of a plastic fork. If you flip the switch and the garbage disposal just hums and does not turn, it is jammed. Usually, with a just a few tools and steps you can get it working again on your own.
Turn off the power for the garbage disposal at the main circuit breaker. Test to make sure the power is off by turning the switch to the "on" position. If it doesn't hum now, the power is off. Turn the switch back to the OFF position. If the plug is accessible, you could also unplug it.
Put the plunger handle into the disposal at an angle; try to spin the impeller blades inside the disposal. Most of the time you can clear a jammed disposal this way.
Locate the hole in the center of the bottom of the disposal, which is under the sink.
Engage the flywheel and turn it back and forth until it turns freely.
Extract the item that got stuck using needle nose pliers. If you prefer, use a wet-dry vacuum to suck out the debris.
Turn the power back on at the circuit breaker or plug the disposal back in. Turn on the cold water and turn on the switch. If the disposal is not turning freely, repeat the steps.