Abstract: A chaser or cascade-effect icicle light set includes a transversely extending common wire portion, and a plurality of transversely spaced, parallel light strings depending from the common wire portion. Each light string defines a plurality of lamp sockets physically disposed in a series. The lamp sockets of the plurality of light strings are organized into a plurality of series-wired sets corresponding to given points along the lengths of the light strings. All lamp sockets of a given set within a given light string being electrically disposed in series. The number of the lamp sockets in each light string is an exact multiple of the number of sets. Controls for actuating and deactivating the sets successively produce a cascade wherein each set of each light string flashes on and off in substantially horizontal unison as a set to provide a cascade-effect.