Case for the popular LED cubes, fits the 4x4x4 kit that is widely available on eBay and other places. My board is 82mm square and the hole centres are about 73mm. A STEP file is available in the downloads.

Print the base in the STL file and cut the parts in the DXF on a laser machine from 2mm acrylic. Bolt the circuit board to the base, glue the acrylic panels into a box and slip it over the LEDs. There is room for a 9 volt battery in the base and a position for a switch or pushbutton in the front.