Bly Manor has North American early 20th century push button light switches and sockets throughout the building despite being set somewhere in Essex, England. Buildings electrified in early 20th century England would have had toggle switches and round two pin sockets. By the 1980s, when the series is set, there would have been modern UK sockets and switches if the building had ever been rewired. Henry's office and Peter's flat have the correct UK switches.