A set of neon LED signs based on the Portal video game series designed to work with 12V neon LED strips like the ones found here. These strips require 12V DC adapters of at least 2 amps (see the specifications on the product page - 2 amps is enough for the length used in these signs).
The bases have a dedicated spot to fit a standard 12V DC barrel adapter like the ones found here.
Best printed in PETG or another heat tolerant material as the LED strips can get warm enough to make PLA warp/sag under their own weight.
The author hasn't provided the model origin yet.