If cost is no object, there is always the $75 "Motion Activated Security Light" at
http://www.pplmotorhomes.com/parts/rv-lights/motion-security-light.htm.
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The webpage says:
"Added Security for Overnighting in Walmart Parking Lots, Truck Stops, or Roadside Parks.
At Last!! RVer's now have a Motion Detecting Security Light that comes on automatically when someone comes near. Not only will intruders reconsider approaching your rig, but you will enjoy the convenience of having the porch light come on when you come in at night. The sensitivity can be adjusted from 10 - 25 feet and is not activated by small animals.
These lights are simple to install replacements for your existing porch light, usually using the same wiring and hole pattern. Known as the Smart Light®, it can function as a normal entryway light, but its functions expand to include motion detection, battery low detection, and daylight automatic shut off.
The Battery Monitor function features a blinking red LED light when battery voltage drops below a predetermined level and will turn off the unit if in the 'motion detection' mode. The battery monitor light blinks blue if the unit is in the motion detection mode, and the battery has an adequate charge."
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I am also searching for exterior lighting options and while this looks interesting if you want to automatically scare the raccoons away as they pass by your trailer at night, $75 is quite a bit of money if all you really need is a basic light.