forget the booby trap wire for perimeter, to detonate the ied, or don't forget i know...anyway...everything is wireless, so my best choice is

Spy Net Laser Trip Wire | eBay

If an intruder breaks the laser beam then the alarm will sound to alert you. Includes laser transmitter, 2 mirrors and a receiver unit. Need it in a hurry?. All products are electrically checked, tested and repaired by our factory. | eBay!

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