I will be gutting the camera and using the plastic housing to mount the laser. Since I'll be destroying the camera, I decided to use one of the "wired" cameras. The wireless cameras are still quite useful to me, so I've put them off limits for my projects...for now. The water sensor will be used as a contact/no contact interface into the Homesight system. I used a water sensor rather than a door or temperature sensor because I won't really lose anything if I fry it during my experimentation. I still find the door and temperature sensors useful. The challenge is to build a small circuit that can open or close the sensor's contacts based on presence/absence of the laser light and squeeze that circuit into the battery compartment of the water...er...I mean, laser sensor.
I should mention that I will be using a laser ripped out of a really cheap laser level that I found on clearance for ~$0.50. Cheap. You get what you pay for when dealing with lasers. In this case, that's a good thing. If you hook up a really powerful laser to this, you'll burn through your sensor, your house, your neighbors house, potentially setting fire to your sensor, your house, your neighbor's house. Heck, you might get lucky enough to blind your intruder or slice his legs off at the knee, or burn the hair off the neighbor's cat, etc. The risks outweigh the rewards though, so just go with your typical laser pointer style laser. K?