Looking over my pre-nap time round of blogs, I was reminded of a situation that came up a few years ago. I had a storeroom that kept getting broken into. The police were about as much help as a BB gun on an elephant hunt.
Since reports were not getting the job done, I found a genuine police siren in the local junk yard, scrapped when the local department went to cars with 12V ignition systems. A quick lash up with a magnetic switch on the storeroom door, a fifteen second time time delay, and a hidden microswitch gave me about 10 seconds to disarm the siren. Which was extremely loud in a 12 X 12 foot masonry room.
A couple of days later the locals called me to come turn the siren off. They never found the intruder – but he (she?) left a conspicuous trail of brown to the alley. And I had no more break ins.
A similar lash up with a hard wired siren and a panic button might be useful.