I have a small cupboard under my stairs and I installed the sensor on one of the steps (well the closet ceiling) to illuminate a bit otherwise it was completely dark and the sensor works very well there, there is no direct passage if the closet is closed it will not turn on unexpectedly. The only catch was that I had to put super glue on the adhesive so that it does not fall. Once stuck you can disengage the part where you put the batteries for change once worn, I took rechargeable batteries so no problem with that.