Poltergeist: The Legacy (1996) : 3x11

Kat is on the job when the team is put in charge of cataloging and disbursing the bequeathed estate of Hanney Ellen Keane and Derek makes a grave error. Taking a few drinks from a cursed Irish Jug causes two ne'er-do-wellers escape from the Jug and possess Derek and Milo. Once the boys realize what year they're in and the fortune the one called Derek possesses they soon decide to stay awhile but before they can enjoy the riches they must get rid of the women. Being the only one that sees the two impostors for what they are Kat must think quickly and convince Alex to help her as Rachel is nowhere to be found.