Here I created a little Birthday Presents with two secret compartments for my friend. If you want to print the model some 6x3mm Magnets are required. I'd propose, that you print the “Magnet test fit Print” and see that the magnet is secure in there. Then you can print the hole model. I finished the model just before my friend's birthday and there might be some minor mistakes, if they are please leave a comment about it. If you want you can adjust the model to your Preferations, for example using the provided Fusion360 file.
The author hasn't provided the model origin yet.