An electrical distribution assembly for use in a modular wall panel assembly, which includes an electrical harness with a conductor carrier with a first carrier side, a second carrier side and a plurality of conductors therein and a connector electrically connected to the plurality of conductors and the conductor carrier. The connector includes an electrical connector port, and a modular receptacle connected to the electrical connector port. A first bracket is positioned on the first carrier side and a second bracket is positioned on the second carrier side and directly connected to the first bracket. An add-on modular receptacle is mechanically connected to the first bracket or the second bracket.