Lite Bright
had 2 of these as a kid.they kind a hazard 1st one i had left under covers and it melted surprised i never burned the house down.
they came with pre designed ones so could make their designs of clowns and animals or blank sheets where could design your own. it was a metal screen with bright light behind it put in little clear plastic pegs that lit up different colors from back light. this toy got quite hot too.
Lite-Brite was invented by Joseph M. Burck came on market in 1967 was licensed to hasbro toys it made top 100 toys of all time list from Time magazine.
remember this commercial
I use to have this too, but it's weird that I don't remember it having a box to make the pieces light up.