Round plastic surface mounted light switch. Probably made in the 1950s.
This hideous mess is a small round light switch which someone has covered in pink gloss paint. The two holes either side of the switch are for the fixing screws, which secure the cover to the baseplate.
Designed to be fixed to a wall or other surface, with wiring entering from behind. Typically these would be fixed to a square or round wooden block.
The back has various wording moulded into the plastic. The remains of one of the wires can be seen bottom left. The other wire connected to the top centre terminal. Note there is no provision for any earth wire, this item being from the 1960s or earlier when light circuits typically did not have any earth connection.
The other hole bottom right would be for a third terminal if this switch was a 2-way type, the same plastic moulding being used for both types.
The switch mechanism is very simple - the plastic rocker presses against a piece of sprung metal, which disconnects the circuit. In the other position, the metal spring is released so the two contacts are connected.
With the cover removed, most of the exposed metalwork is live, in contrast to modern switches which typically have the entire mechanism enclosed in plastic, even when the switch is not attached to a backbox.