Sonoff T1 EU to UK Converter Plate

I live in the UK and accidentally bought an EU Sonoff T1 Wifi connected Touch switch.

European switch housings appear to be approximately round with some flats, whereas UK ones are square. As such, when the EU switch is in the UK backbox, it can rotate and can actually unscrew, exposing the live mains wires.

This plate fits snugly over the nearly-round body of the EU switch, but is also a tight fit inside the UK box so the switch can no longer rotate in the housing.