A compact flashlight is provided having a base with an interior recess for permitting reciprocable movement of a disk battery. The base includes a bulb having a first lead that extends along the bottom of the interior recess. A second diverging lead extends from the bulb to an area along an upper side of the recess. The battery overlies the first lead so that electrical contact is made with the bottom portion of the battery. A carrier overlies the battery and includes a boss portion extending into an opening of a cover that encloses the base. Forward thumb pressure on the boss portion moves the battery from a bulb-off to a bulb-on position when the battery comes into electrical contact with the second diverging lead. This results in illumination of the bulb. The carrier is provided with resilient members extending outwardly from the back end of the carrier. The resilient members engage a corresponding detent in the housing and maintain the battery in an off position. Release of thumb pressure allows the resilient members to draw the carrier/battery back into an off position. The flashlight may exist as a self-contained unit or it may be incorporated into a variety of outer housing structures. It has particular applicability for use in thin housings that have a card-like shape.