In the Phineas and Ferb episode "[S1E9] One Good Scare Ought to Do It!", Phineas and Ferb build the ultimate haunted house to cure Isabella of an extreme case of hiccups. This episode is unique for being a double-length (21-minute) special that originally premiered as a "never-before-seen" bonus on The Fast and the Phineas DVD before airing on Disney Channel in October 2008. Plot Summary
“The action sequences between Perry and Doof were top-notch... Candace gets shafted here, in more ways than one, but it didn't really need a lot of expanding.” Reddit · r/phineasandferb · 7 years ago [S1E9] One Good Scare Ought To Do It!: Parts 1 & 2
“One of the best Season 1 has to offer... the songs were nice. It seemed a little over-the-top how Phineas and Ferb would create a haunted house just to cure a case of the hiccups, but then again stranger things have happened.” Reddit · r/phineasandferb · 9 years ago In the Phineas and Ferb episode "[S1E9] One