A combined earthquake sensor and night light having a base with a bottom portion resting on a support surface subject to vibrations. A top portion of the base is provided with a reflective surface and a centrally mounted lamp. A transparent cylinder is mounted on the base member to suspend a multifaceted spherical crystal above the light source by means of an elastic helical spring to enable the spherical crystal to move in all directions. Vibrations generated by an earthquake are transmitted to the base member causing movement of the crystal giving a visual indication of the vibrations by light reflection and diffractio. In the static mode the unit serves as a decorative lamp.