Brodie & Hume Plumbers Edinburgh

Not too sure what this is other than it is brass and has the name of my ancestor, William Hume when he was in a plumbing business in the first quarter of the 19th Century with John W Brodie in Edinburgh at 27 West Register Street. Size 95mm x 65mm

A contact on Google+ suggested that it looked like an electrical light switch cover so I had a quick check on the internet and found this:-

http://www.buildingconservation.com/articles/lighting/lighting.htm

"In 1879 Thomas Edison beat rivals like Sir Joseph Swan to perfect the first viable incandescent light bulb. One year later, Cragside, a rambling mansion near Newcastle designed by Norman Shaw, was the first house to be lit electrically, using Swan's 'electric lamps'.

By Queen Victoria's death in January 1901, electric lighting was still in its infancy. Gas lighting was common in the cities and larger towns, supplemented by candles and oil lamps, but in smaller towns and villages and in the countryside lighting remained almost exclusively by candles and oil lamps. All the principal forms of lighting were thus in use at the same time, and it was not until after the First World War that electric lighting finally emerged as the predominant source of light in the home."

Sounds like Brodie & Hume would not have been making light switch covers which makes this object even more perplexing.

Have you got any idea what this is? Please let us know.