External GPU cases have been around for a few years. You take a desktop graphics card, stuff it into one of these cases, then plug it into a laptop for a performance boost in graphics. Ideal for turning a sluggish laptop into a gaming laptop.
One design idea for such a case is the Ghostbusters ghost trap. Not only would it be life-size, but it could store 2 graphics cards (I don’t think external GPU cases can juggle multiple cards just yet). Also NVIDIA cards have LED logos on the side, so they can emit a ghost green light as well, perfect for a ghost trap.
Dave's Geeky Ideas 