Also try
here.
The manufacturer didn’t give the size specs.
Wickes own brand would use OTS (off the shelf) cheap parts. Nothing OEM there.
Take the switch to an electrical wholesaler like TLC or CEF.
We use these types of switches all the time with built in cupboards with lights inside.
You can use a different footprint and ‘pack’ the plastic moulding. Is this the main power switch for your mitre saw?, you could buy a soft start with speed control and adapt the housing to fit.
Martin