Some of these may be key switches (to control access).
Unless local codes require otherwise, this will most likely be a key switch.
It is activated by a key switch either inside the elevator itself or on a centralized control panel in the lobby.
The man turned the key switch one more time and the elevator froze in position with the doors open.
A Department of Corrections official then turned a key switch in the wall behind the electric chair, activating the system.
Kong's hand shot out to his own key switch.
Class-3B lasers must be equipped with a key switch and a safety interlock.
There was a bulb sticking out of the wall, with a key switch.
The key switch is used to return the escalator to service after it has been stopped.
I got up to my feet and reached up and turned the key switch of a hanging bulb.