While you won't be dangling from your ceiling like Tom Cruise, you will be able to code a Raspberry Pi to set off a buzzer if somebody trips a laser, and it's actually simpler than it might seem.

The raspberry pi is overkill for this, but I suppose you use what you have. You could do something similar with an openwrt router using a GPIO. It will even host the CGIscripts necessary for it.

Raspberry Pi barcode scanner “The Zero Barcode HAT has an on board DE2120 scanner module with a 1.14” LCD screen of 240 x 240 pixels resolution. The device has an on-board scanning button ...