Bryan, go up the road to Cullercoates and ask at ESR, an electronics bits n pieces shop on Station Rd opposite the cop shop (or they were, last time I passed by). All it needs is something of the right size and shape and performance unless its one of those incredibly dangerous safety switches. While a qualified form filler is a legal necessity for house wiring, its really the last sort of person you want mending an appliance.
There is no fear of the law, as until it gets plugged into the mains, its just a lump of metal and plastic, not a part of the house wiring. And yes, they do sound like they are playing at being morons for profit. You dont need to join the game.