Zero chance of finding anything specifically listed as a dedicated spare. Your best bet is to look for a suitable switch in the varuoie professional suppliers : RS components is often useful. It'll probably be some kind of double pole rocker switch, rated at least 16 Amps.
You might be able to find a makers part number on the old switch and do a Giggle search for that and her some idea what you're looking for..
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix d.i.y tools.