I have had a couple of people as me about how I was able to wire up our industrial outdoor lighting so that it comes on automatically at night and goes off in the morning. At first we thought about making it motion activated like our old one, but the reality is that we would probably prefer to have a porch light on all night regardless of any motion in the area. We were able to find a cheap photocell that activates the light fixture in low light conditions. The trick was finding one that would fit nicely in the waterproof junction box that came with our light. The one we settled on is pictured above, and was available at our local hardware store for around $8. They are commonly used for outdoor pole lights. I was able to find it online at farm-home.com, but I am sure there are other places that have it as well. To attach it to the fixture you simply unscrew one of the access holes in the junction box (we used the top one) and insert the photocell. It has a rubber foam gasket to keep it water tight. The only two downsides to the $8 trick is that photocell usually only last around 5 years, and they can only control incandescent lights.