You basically need to just break the coil holding circuit identified as Z in the diagram. You will need a microswitch contact that is NC so when operated it breaks the power to the coil.
Problem is getting the balance right so its sensitive enough to activate and get the mouse/rat without breaking your fingers as you try and place it down on the floor without it getting you.
I only lend tools to a select group who i trust and i know if i needed something at a pinch they would do the same.
I also have a rule "Never trust a man who ownes no tools."
I feel if i need to borrow a tool more than once then i probably need to own that tool.
Shouldn't be a problem, get some gas and a fresh reel of wire if your wire has any signs of surface rust and fire it up. Good basic built proof proven designed machines.
I think somewhere around 11/12 I was already fully aware as dad built me a go-cart with a Suffolk lawnmower engine on, we worked on together and span it around the garden.
I remember whenever I was at the factory the welding room was one of my favourite places, The big oxfords, oxyacetylene for...
For a small portable of a 13A socket, you cant get much better than this.
https://www.machinemart.co.uk/p/clarke-xepv1650-industrial-air-compressor-230v/
If the budget won't stretch then at least of for a belt-driven set up rather than a direct drive.
I can't make it out If the copper as touching the earth then the fuse would just blow on insertion into a socket.
If it wasn't touching the E then not much would happen as L down the L&N wires so the device just wouldn't work.
What about a heated jacket, not the compleat answer but might help.
https://www.protrade.co.uk/product/milwaukee-m12hj-12v-black-premium-heated-jacket-body/?variation=44939
>To slow just seen above post.