I found a 3.5 inch by 4.5 inch, 1 inch deep platic box in the upper bedroom cupboard.
I removed it and it contained electronics, a 9 volt battery, and contacts to get 12v from wires behind cupboard.
There is a tag with "TREKMATE 15" on it.
Google searchs on Web and Beamalarm revealed that it is part of a Trekmate Security System, perhaps a motion detector and that Foretravel installed it as an option.
Where would I find the main unit, other models, a key fob, and instructions?