The message . com
from "dcbwhaley" contains these words:

Apparently vibrations occur at mains frequency and this can cause the
screws to loosen because electricians, unlike other engineers, haven't
discovered self locking screws or screw locking compound yet :-)

Braqss screws done up tight enough seem to work fine. When they squeak
it's good and tight.

--
Skipweasel
Pay no attention to that man behind the curtain.