This is related to my wash machine. When switching capacity in loads, if the switch is not totally clicked on either, large, medium or small, the washer does not recognize any and continues to fill. This has no auto shut off and can continue to fill for hours or until someone realizes the problem. This has cause some major flooding and I realize should have been taken care with first episode. Is there a problem with the sensor switch, seems like wash machine should be equipped with any auto shut off??

There is no auto shut off. The switch you're referring to is the pressure switch. It works by sensing the pressure created as the tub fills with water. The switch must be actually on a setting. Unfortunately, that's all there is to it.