I designed a simple latch box that is print in place and can be scaled to whatever size you need it, the only limit is you printing plate. The current size is around 600cm^3. This simple box can be used to store whatever you want from jewelry to other 3D printed trinkets, or something useful in your office or shop.

I printed it with supports, but realistically you shouldn't need any. Print in the orientation with the lids open and the hinge in the middle. After it's done printing and cooling, take it off the plate and try and close the lid, it should snap shut. You need to put in good effort to open it, so it won't accidentally. I even did a drop test from about a foot off the ground and it stayed closed.