Over on YouTube Paul from "Tall Paul Tech" has uploaded a video showing how he was able to reverse engineer the wireless protocol used by a simple restaurant beeper (aka 'burger pager') notification system that is used to let customers know when their food is ready.
By reading the label on the base unit, Paul found that the beeper system transmits at 433 MHz. He was then able to record it's transmissions with an RTL-SDR. Then using Inspectrum, he was able to determine the bit string and the symbol period.
From there he was able to use a GNU Radio program to replicate the signal, allowing him to use a HackRF to activate the beepers on demand.