When you have more than one USB mouse receiver and you don't want to leave them in your laptop indefinitely you want somewhere to put them. I ran into this issue particularly because I have a mouse that does not have a spot to put its USB receiver.

This box is a snap fit and the lid slides on and off. It is a little bit stiff and tight the first time but after snapping it on and off a few times it is really smooth.

I printed mine in PLA, PETG would probably work a little better with its increased flexibility. 

For Printing:

The box prints right with the holes facing up. The lid has the flat side down with the rails facing up. This avoids needing supports.