I put up a lamp post for my wife. Included with the lamp post is photoelectric eye so the light will be a dawn dusk type. When I wire it direct it turns on and off at the flip of a switch. When I wire in the photoelectric eye and cover the eye with my finger it does not come on. Shouldn't it come on when I cover it with my finger? It it likely the photoelectric eye is bad? What is a good way to test it?