Rusty Electronic Gadget

I have seen this in the garden before, but not really taken much notice of it, but today I took a good look at it to decide it must be an Electric gadget that the old man had in his Greenhouse when he lived here.
Interesting object.
I found this information online about WEMCO.
Wandsworth Electrical Manufacturing Co. Ltd (WEMCO). Founded in 1904 in Birmingham by Edward Thomas Davies, Arthur Reynolds and Francis John Ritchie., manufacturers of switches, plugs and sockets. The name Wandsworth has been chosen as a founding member came from the Wandsworth area of London. The still existing, independent, Wandsworth Group is now based in Woking, Surrey.