"Removed a wall plate and found this mirrored contraption fitting in some sort of electrical junction box. Any idea what it is?"
A: "It’s an old alarm motion sensor. Break the beam, set off the alarm. Look at the perpendicular wall for its other half. Could just be a small mirror or reflector as well on the other wall to bounce the beam back."
They also used to have firing ports in the billboards along the highways.
Ha my thought initially but realized it is being used to cover a hole...(Probably a location for a control panel in a different situation), since it fits so well
We have these in our elevators as well. There used to be a telephone mounted there to call the front desk in case the thing got stuck. Later they got obsolete because there had to be automated warning systems
This is part of the weather station system. There is also a wind speedometer above the plaque. And I confirm that the upper temperature is air temperature and the lower temperature is the road. Warnings, for example about black ice, are also displayed there