In first season episode Oasis, the Enterprise crew are searching for resources aboard an old shipwreck on an apparently uninhabited planet, when they discover a hidden colony of Kantare shipwreck survivors. When inconsistencies in the colonists' stories result in a confrontation, the truth is revealed: Only two of the Kantares are flesh and blood, with the rest being merely holograms; recreations of those who died in the crash. Liana, one of the two survivors, eventually deactivates the holographic figures by removing these modules from a control panel.
Machined aluminum and other metal components, with transparent acrylic tubes and paper graphic decals. No electronics.
From It's A Wrap.
