Here "set apart" means that Micah "dedicated" or "ordained" him. Alternate translation: "Micah dedicated the Levite" (See: [[rc://en/ta/man/translate/figs-idiom]])
Here living in Micah's house is spoken of as "being" in his house. Alternate translation: "lived in Micah's house" (See: [[rc://en/ta/man/translate/figs-metonymy]])