The idea of a lamp sign startet with the flame lamp: https://www.prusaprinters.org/prints/84636-de-warmste-week-lamp
I made in the same style a heart Lamp.
Added a 5V led strip with usb cable, just as the flame;
I also glued a “vibration activated MP3 gift card”-module inside, so that every time is is picked up, you get a personal message :-) (See: Aliexpress)
The author marked this model as their own original creation. Imported from Thingiverse.