In the process of making my own 3D printer I did the usual thing and twisted the limit switch wires until I had a better idea. Like most everybody else I have an excess of USB cables. They make a fantastic shielded cable exactly suited to limit switches. They are low or no power and shielded to boot. The STL of the magnet is just a place holder. So you can ignore it.

Take your trusted side cutters and cut off both connectors at the ends. Peel back the insulation and you will see the shield. There usually are four wires. Red, black, green and white. As they are small and we only need two for a limit switch twist red and black together and connect to one side of limit switch. Twist white and green together and solder onto other terminal of limit switch. Make sure to cut the shield away and the shield wire as well (the bare wire).
At the circuit board side do the same with red black and green white. solder a wire onto the bare shield wire and connect to ground. You now have a perfectly shielded noise proof cable on the cheap.
Make sure you ground the shield at only one end, otherwise you may create a ground loop. Not good!