Visit this project on GitHub.
For my ShotBot project (more on that hopefully soon) I needed a holder for a WS2812 module — so I designed one with FreeCAD and 3D-printed it.
You can find the files on Thingiverse and in the ShotBot GitHub repository. It fits modules with a size of 54 × 10 mm (≈ 2″ × 3/8″) and two 3 mm (≈ 1/8″) holes at a center-to-center distance of 26 mm (≈ 1″), but if you have a module with different dimensions you can modify the design in FreeCAD.
The module snaps nicely into place, for extra security you might want to add two drops of glue at the hole positions. Here are some photos of the part used in the ShotBot UI module: