Abstract: A ribbon of light with a bright spot moving thereacross is generated by a series of sequentially located indicator lamps or LED's, sequentially energized by a ring counter which, in turn, is enabled by a time-based decoding circuit. The time-based decoding circuit has applied thereto, preferably by a magnetic pick-up, sensed signals representative of the ringing current in a telephone network, and decodes when such ringing signals are received, rejecting, however, all other signals on the telephone line such as, for example, calling or dialing signals, stray noises pulses, or the like. Preferably, eight lamps are provided, each one flashing for 1/8 second, with a ring counter cycling rate of 1 second.