This is a portal button I made some time ago. The button portion moves freely on rails inside the base.

I designed it to use as a toggle switch to control a relay that would power the monitors I use on my desk so I wouldn't have to reach behind them and find the power switches every time I sat down to use the computer. It also makes a cute desktop ornament!

I don't have the circuit diagram handy but I will attach it to this post once I am able to find it! It made use of the ~30mm diameter round PCB from the old RadioShack round PCB kit which you will have to find a new vendor for if you want to use it as is...