There are a few options of PIR sensors that can be flush mounted in a wall, such as 753, or any of the ceiling mount sensors, depending on what range and angle you want to sense, but the best option for a stand alone sensor would be the Iconic 41EPIRM module mounted in an Iconic plate. There is also an Iconic nightlight (3025NW) that fits on an Iconic 3025G double horizontal socket that has a PIR sensor and daylight switch that asctivates an inbuilt LED. (This does not have an independant output to switch any other load.)