In most kitchens, the garbage disposal is controlled by a standard wall switch. Flip the switch on, and the unit turns on and grinds up whatever food waste has gone down the kitchen sink drink. Turn the switch back to the off position, and the garbage disposal shuts off. The switch isn’t turning on and off the disposal directly; instead, it controls the flow of power to the electrical socket in which the garbage disposal’s power cord is plugged. The disposal is always on. The switch determines whether or not it has access to any power.
Underneath your kitchen sink, you will find an electrical outlet with two sockets. One socket always has power; the other socket’s supply of power is controlled by the wall switch. If you unplug your garbage disposal in order to clear a clog, plugging it back into the always-on socket will turn on the unit. The wall switch has no control over it, so it won’t stop running if you turn off the switch. Unplug the garbage disposal’s power cord from the uncontrolled socket, and plug it into the correct one to solve the problem.
If you haven’t unplugged your disposal recently and the switch worked to turn it on a few moments before, then the problem likely is a fault in the switch. The wiring has failed, and it is no longer controlling the electrical socket’s power supply. Unplug the garbage disposal, and contact an electrician. A professional can determine the cause of the failure and repair it so it will not happen again.
If you do not solve the issue of your garbage disposal continuously running, you will need to replace the unit. The motor is designed to run only for short periods of time. It can overheat; in the best-case scenario, the unit will jam up until it finishes cooling down. In the worst case, the motor will burn out, and you will have to replace the disposal with a new one.