Snooping around other people’s houses

They used to be someone’s private home, now they’re open as small-time capsule museums:

■ Musée Gustave Moreau, for his steampunk staircase. 14 Rue de la Rochefoucauld, 9ème; musee-moreau.fr; closed Tues

■ Musée Jacquemart André, for the winter garden, an exotic vestibule under a glass ceiling designed by the ...