Central Vaccum Wiring use?
Usually for causing the vacuum to turn on when you plug a hose into the outlet, or plug a hose into the outlet and turn the switch built into the hose on.

It's generally a low-voltge relay setup in my experience.

Normally they would be connected to terminals on the vacuum outlet - not quite clear what's going on if they are just twisted together (and appear to have been painted at some point.) What is your normal procedure to turn the vacuum on - that might shed some light on this odd arrangement.