Step 1: Make it!
2. Next, cut a small piece of plastic canvas to insulate the spring from the pipe.
3. If you are not using an existing spring, wrap a tight coil of steel wire around a pencil or similar item to make a tightly wound steel spring.
4. Zip tie the spring to the plastic canvas.
5. Insert into the pipe.
6. Attach a wire to the spring and one in the hole drilled in the copper pipe.
When the magnet comes close to the top of the pipe the spring gets pulled over and makes contact with the copper pipe
When the magnet is removed, the spring goes back to the rest position cradled in the plastic canvas insulation.
Congratulations, you just made a quick and dirty Reed Switch!
Please leave (constructive) comments if you have ideas to make this better.