I was at the castle about two weeks ago and spent the better of a long evening and most of the following morning and afternoon exploring (a feat given it's 50,000 square feet in size). Also to note is lighting designed by Thomas Edison in one of the rooms.
I didn't concentrate too much on the chandelier as there was lots more to talk about but was able to confirm the switching: three single pole switches for the chandelier, among others for other chandeliers and banquet lamps (although it didn't seem to be enough). Given I was everywhere from the top of the roof to navigating through the tunnels, I saw too much of everything to really hone in on one item. The chandelier is pending restoration though with about half of the sockets without power.
The hall it is in has its own subpanel, cleverly set behind a half-column which was cut to swing open like a door.
Also, I was able to note fluorescent floods along the ballroom balcony to illuminate the stained glass. The outside of the castle was dark and would benefit from lighting. Lots to be done there though with some very exciting projects possible.
