Check the plug for the third prong. This prong usually bears the brunt of being yanked from the outlet, which sometimes results in breaking off the prong. Some people also remove the prong so that the plug can fit into a handy outlet.
Look for any breakdown in the case or cabinet of the appliance. Most contain insulation, and the breakdown of the case can lead to problems if the appliance gets wet. Insulation won't protect you from electrical shock in that instance.
Guard against using an adapter plug that turns a three-prong plug into a two-prong plug. The designers put that third prong on your appliance plug for safety.
Inspect the circuit breaker in your electrical panel. If it is off, turn it on and try the appliance again. If the circuit breaker trips again, your appliance may need repair.
Shut down the appliance if you feel a slight tingling while operating it. The tingling is an electrical shock and indicates that the appliance is not grounded properly.
Test the appliance by pressing the Ground Fault Circuit Interrupter button. If the button trips again, there is a problem with the circuit. Test the wiring with a multimeter.