A random question: My place was built with all the plumbing for a central-vac system that I have no intention of using ever. What alternative uses might I have, for this idle series of tubes? Right answers, speculative answers and hilariously wrong answers equally welcome.
@mhoye Home mesh network
@grmpyprogrammer why do I need tubes for that?
@mhoye For running cables connecting to the  switch (you did say “wrong answers”)