Originally Posted by Arefbee
As I recall I have heard that the late night need to visit the restroom leads to a lot of sleep walking. Maybe try restricting fluids after dinner.
I've heard similar. Basically the sleepwalker is trying to go to the bathroom, but often not finding the right location. In e-dad's case, the time they caught her in the closet she might have been trying to find the bathroom light switch. (If it's a bathroom thing.)
Note: I only know about this from my own research about bedwetting crossing into this territory. Sometimes just reducing fluids isn't enough if the person isn't producing the right hormones that tell the body to shut down urine production at night.
But that's all up to e-dad to work out with his family. Our concern is the question he raised, about the best way to detect his sleepwalker might be leaving the trailer.
In that case, I'd probably look at a portable door alarm. (Something like those found here: Door & Window Alarms - Security Systems - Home Security & Video Surveillance - Electrical¬*at The Home Depot
Though I'd also take the time to research the least audible one. Some of those at 120-130 db might be a little traumatic to the sleepwalker.
Edit: Being curious, I started clicking through a couple of these. This one might work for you: http://www.homedepot.com/p/SkyLink-D...c202Z12kyZ12kz
It looks like it can be set to either alarm or just chirp, so on chirp it won't be loud, and the siren unit can be placed in the master with just the sensor on a door. It also says it's expandable so you'd be able to sensor both of your outside doors.