The Prism nightlight isn’t exactly a prism, although it’s shaped like one. I think it should be renamed as the see-saw nightlight because of how it works. There are no switches or anything, and no, the light isn’t equipped with sensors so that it automatically turns on or off. The switch is actually the entire lamp itself.
Just pivot it to one side to turn it on and back to the other to turn it off–like a see-saw.