This simple 3d print takes little time, but makes for a fun light. These lightbulbs are inexpensive, waterproof, and are self-contained. I usually get them online in packs, which averages out to less than a dollar per bulb. See the attached images.

You can also place the eggs on top of standard tea lights, like the kind that mimic a candle (don't use a real candle).

Simply print the egg, print the stand, and have fun. I only use a skirt for plate adhesion and no support material needed. The walls are about 2.5mm thick. I printed at 20% infill.