A control unit comprising a light guide is formed and positioned in a circuit board for providing visual indication to a user of an appliance, such as a cooktop. The light guide receives light from a source, typically in the form of an LED on the circuit board, typically positioned laterally to the light guide, and the light guide receives and directs the light to the user. In some embodiments, the light guide is positioned behind a cover, which may have indicia thereon for providing operating information to the user. Portions of the light guide may be coated with an electrically conductive coating so as to also form a portion of a capacitance touch switch for detecting user input for controlling operation of the appliance.