Careful with this.. it's the Internet. As seen in this scene from UK sitcom The IT Crowd in which a pair of mischievous IT workers play a prank on their tech-illiterate manager.
3D printing is really not the best way to build a full-size working replica of the prop, as the original was made with cheap off-the-shelf parts and there's already a great Instructable with all the info you need to build your own. Though this copy is modelled at full-size, I imagine it being much more useful for scaling down and printing as a desk toy or prop for action figures, dioramas, and such. The ones in my photos are printed at 1:6 and 1:12 scale.
This model is primarily based on measurements gleaned from that Instructable, many thanks to author Melty Mcface for doing the work.
There's a complete STL ready for scaling, printing, and painting, as well as a version without the simulated "LED" in case you'd rather stick a craft jewel or something on for looks.