https://www.printables.com/ - one of the sites with free and paid files for 3D printers.
a) Something for Halloween: https://www.printables.com/model/1046613-updated-candy-dish-or-candle-lamp-inspired-by-lego
b) But also something more useful: https://www.printables.com/model?ordering=liked&period=all-time
Just download the files, set up the printer, connect a spool of filament (thick plastic thread) to it, wait and ... you have a new item.
Agorism?