I bought several of the new SmartThings buttons. They come with adhesive pads for mounting on various surfaces. That's cool, but I'll be repainting walls soon, and then I'd have to replace the adhesive.

Turns out, these buttons also have two small magnets in the base. Excellent! So, here's a little doohickey that you can attach to the screw on a wallplate to give the button a magnetic attachment point.

I used 6mmx3mm round neodymium magnets, they can be found all over Amazon and eBay for cheap.