Synopsis at http://en.wikipedia.org/wiki/The_Haunted_Manor
The Haunted Manor (Polish: Straszny dwór) is an opera in four acts composed by Polish composer Stanisław Moniuszko in 1861--1864. The libretto was written by Jan Chęciński. Despite being a romance and a comedy, it has strong Polish patriotic undertones, which made it both popular with the Polish public and unpopular -- to the point of being banned -- by the Russian authorities which controlled most of Poland during that era.[1]
It is considered Moniuszko's best opera, and also the greatest among all 19th century Polish opera scores.[2][3] However, it is mostly unknown outside Poland.