Abstract: This system for building up electrified lines in the form of double-voltage exposed modules for supporting user appliances, particularly lighting lamps for interior environments, is formed from track pieces of standardized length along which conductors extend to form electrical lines, said track pieces being connectable together with the aid of interposable means including a prismatic box of square cross-section which is open at one of its ends to form various geometrical configuration suggested by aesthetic and/or functional requirements, and being combinable with supports for user appliances, particularly lamps of various types, along their entire length.