A gravity-actuated switch having a switch module with a switch housing and a lid. An electrically conductive pendulum is pivotally secured to the lid via a pivot pin so that the pendulum hangs within the housing and pivots with respect to the housing under the influence of gravity. A first electrical contact connectable to a power source abuts the pivot pin, which is electrically conductive. A second electrical contact is provided within the housing in a predetermined position such that the pendulum makes contact with it when the switch module is tilted by a predetermined amount. When the pendulum makes contact with the second electrical contact, a short circuit is provided across the pair of contacts, thus closing the switch. The switch is incorporated in a lamp assembly provided on the underside of the hood or trunk lid of an automobile to selectively provide power to a lamp so that the lamp is illuminated only when the hood or trunk lid is opened by at least a predetermined amount. A switch composed of a pivoting magnet and a magnetic switch can be used instead of the combination of the conductive pendulum and the curved electrical contact.