Abstract: The present invention provides a security lighting system and method, that are intended to dispel and/or affect unwanted humans or animals (20) by providing lighting that varies with a suitable switching frequency, such as between 5 and 70 Hz. The lighting of a light source (14a, 14b) of the system may be varied by a control unit (12) as to intensity, color, pattern etc., with a preferred switching frequency being between about 15 and 20 Hz for humans. A proximity detector (16a, 16b) may be provided to activate the system when an unwanted presence is detected. Such varying lighting causes feelings of physical and psychological discomfort, which have found to be effective in chasing away animals (20), and dispelling or disorienting humans.