This is an Antique Victorian Lightswitch.
Made of Brass, this is the Dolly Style Switch.
With a Black Ceramic Back to the switch, which is stamped, 'Wandsworth'
The Lightswitch measures a little under 6cm across, (2.3 inches)
The Brass top unscrews from the back, and all works well, and when the switch is flicked the inner bits all do what they should.
In Good condition, I have not polished the brass.
Any Questions, please ask.