Small shelf to display Pokeball Tins (the ones you buy that contain pokemon tcg boosters).

Friction fits on 50mm thick Ikea floating shelf (probably pretty easy to modify to fit LACK shelf which I believe is 36mm thick). Has a small circle cutout to glue in a 20mm x 2mm magnet to keep the tin from falling, but rests on the shelf without it (I wouldn't trust it to stay put if someone slammed a nearby door though).

Possible to print without supports when laid down on its side assuming your printer handles overhangs well enough. If it turns out a little ugly then it's probably still fine because it's practically hidden by the pokeball tin.