My neon ghosty (https://www.printables.com/model/302135-led-neon-ghosty) was a little too cute, so decided to make a more gory version for my Friday the 13th fans!
This 3 color LED neon sign is setup to use standard Neon LED strip lights that can be cut every 1" and holes for running power to each section. Heads up, it is a pain soldering these since you need to strip away sections of the silicon, but the results are well worth it!
Amazon link to Neon LED: https://amzn.to/3sIolhP
This is just an example of what I used, feel free to purchase where you can find the best price!
The author hasn't provided the model origin yet.