There are three installation options:
Remote Installation: Letters are installed directly on building surface. Wiring for each letter passes through the wall to which letters are attached. Electrical connection penetrates the wall behind each letter. In most cases installed above a drop ceiling or other hidden area inside the building.
Background: Mounted to the back of the letter if raceway is not used. If letters are mounted to a raceway the background can be used to conceal the raceway. Aluminum composite material that can be painted any color to add contrast between building and letters.