A candle shadow box that projects stenciled patterns on the room walls.  The box walls are 1.5 mm thick, 100mm wide by 80mm tall.  You can create your own walls in any design software, just cutout the stencil patterns with whatever themed shapes you want. 
There is enough space around the candle that the walls only get slightly warm.  Cool air coming in through the stencils keep them cool.  Still, when dealing with plastic and an open flame, caution is recommended.  Use at your own risk. (I had to say that.)
Modeled in FreeCAD.