Abstract: A universal dimmer switch knob is provided having an inner bore to receive an intermediate member. A plurality of intermediate members are provided in a kit, such that a user may select a particular one of the intermediate members to correspond to a particular dimmer switch shaft. The intermediate member preferably has a non-cylindrical outer periphery and the knob has a non-cylindrical inner bore. The intermediate member is generally A-shaped with a central apex lobe and two side lobes. The lobes are received in notches in the knob. When the knob is turned, the lobes and notches resist slippage between the knob and the intermediate member.