Customer Questions and Answers for Light Switch by Whirlpool

William, There is not a light switch for this microwave, the switch would be the control board and keypad. In order to remove the cover of the unit you would need to remove the unit from installation and take out the screws holding the cabinet in place. If the light is not working you would want to check to see if there is 120 vac coming from the control board to the light assembly. If there is not then replace the control board.