How to connect switch to electric box containing 3 grey (twin and earth) cables?
Looks like a standard UK ring circuit.  The chances are that the top two are two sides of the ring, and the bottom one is to the fridge.  It should be obvious if the fridge outlet is immediately below the switch.
So the two top reds go to the &quot;in&quot; L side of the switch.  The top two blacks go to the &quot;in&quot; N side of the switch.  The bottom red goes to the &quot;out&quot; L, the bottom black goes to the &quot;out&quot; N, and all the earths go to an earth terminal.