Metal Flush Box (Electric Concealed Box)
Metal Flush Box is a container for electric connections, usually intended to conceal them from sight and deter tampering. A small metal box may form part of an electric conduit in a building.
If designed for surface mounting, it is used mostly in ceilings, under floors or concealed behind an access panel - particularly in domestic or commercial buildings.
An appropriate type may be buried in the plaster of a wall cast into concrete - with only the cover visible.
It includes built-in terminals for the joining of wires. (Earthing Connection)
A similar, usually Wall mounted, container used mainly to accommodate switches, sockets.