Former PC repair person:
15 or so years ago I had a pager from my previous employer.
The subscription expired but it still got news bulletins.
One of my clients stiffed me but I couldn't accuse him of taking back
the money he had paid when I wasn't looking.
(I blame myself for being so careless.)
A year or so later he brings that PC in again!
I fix it and this time hold the money as I prepare his receipt.
However....
Between finishing the repair and returning it to the client...
I put a fresh battery in the pager, set it to beep when a news bulletin arrives
and hid it in the void inside the front of the case below the 'start' button.
The result...
Every so often...whether on or off...the PC would beep.
No... he never came back.