Adding photo cell switch to shut off outside lights

While the 12V circuit board would have to be placed in the trailer, the photoelectric sensor is the only part that needs to be outdoors. I built a similar device that turns on my outdoor lights when I flash my headlights that uses the same photodiode - it is mounted in a 2" piece of 3/4" plastic conduit, and has been working for 20 years of rain & snow...