Modular apparatus and methods for ultraviolet (UV) light sanitization of an aircraft. The modular apparatus generally comprises a base frame that is universal, and multiple interchangeable modular kits to adapt the base frame to different aircraft cabin geometries. The base frame has integrated therewith circuitry and devices that control ultra-violet C-spectrum (UVC) light sources that are located on a frame of the modular kit. Various embodiments of the modular kits have five parts, and assemble the same way, for different aircraft cabin geometries.