Abstract: A photosensor cover and kit for detecting a malfunction in a lighting system, wherein the lighting system comprises an illuminator and a photosensor. The photosensor comprises a photocell that detects a threshold amount of light and electronic circuitry in communication with the photocell that signals the illuminator to turn on/off when the threshold amount of light has been detected by the photocell. The photosensor cover comprises a cap comprising: a barrier layer comprising an opening, wherein the barrier layer is disposed over the housing body such that the barrier layer covers the photocell. The photosensor cover further comprises an adjustment element that allows for the expansion or contraction of the opening, and wherein the adjustment element assists in preventing the threshold amount of light from reaching the photocell.