This is a rare backlite Gamecube Sign. My knowledge is that this was part of a big display case at KB Toys. It is in good working order.
I also have a Blue Nintendo Neon Sign for sale as well. The item "Nintendo Gamecube Box Light Sign Translite Rare Vintage Display" is in sale since Wednesday, September 12, 2018. This item is in the category "Video Games & Consoles\Video Game Merchandise".The seller is "thejellispicker" and is located in Newark, Ohio. This item can't be shipped, the buyer must pick up the item.