An integral conduit modular lighting system that has a light board having circuitry that is secured to a heat sink with an adhesive layer. The heat sink has a gasket in order to securely connect the lighting system to a preexisting conduit body such that the lighting system withstand a high pressure wash without leakage to the board. The heat sink also has opening that mate with openings of preexisting electrical conduit bodies to provide installation of the modular lighting system to existing electrical conduit bodies.