Hi @CharlieG think of wood as a bunch of tiny straws glued together. These straws are flexible when only a small number are together. Think of a thin wood shaving, it's flexible. So if you weeken this straw structure in the right places, like the saw marks at the back of the switch the wood starts to become springy. It took me a while to figure out the right number of cuts to get it springy. But got there in the end. Watch the build video more for more:
I figured it out when I saw the other photo of it next to your lamp you made. I like that too.