Water over flowing
I will assume that your machine does not run. It just fills and fills until it overflows and you shut it off.
This is not to difficult to troubleshoot and repair.
There is a plastic hose that runs from the bottom of the wash tub to a pressure switch inside your control panel. This hose is flexible and between the size of a marker and an ink pen. As the water level rises, the air in the tube is pushed up into the pressure switch. When the correct pressure is reached, the switch shuts off the inlet valve which will stop the water flow.
You must make sure that the hose is not pinched, cracked, or disconnected on either end. Any of these will give the pressure sensor/switch a false reading.
If the hose is okay, then the switch is your most likely problem. It simply has 2 electrical connections and the hose running to it. Replacing it should be fairly simple and inexpensive. Good luck.