The Foster Brothers (1976)

Original title: Süt Kardeşler

Saban, Ramazan and Bayram are sailors in an Ottoman Navy and Hüsamettin is their commander. Hüsamettin's aide Ramazan, Saban who is foster son of Hüsamettin's sister and Bayram who is married to Hüsamettin's niece stays at Hüsamettin's family residence. Hüsamettin's sister thinks Ramazan is her foster son Saban when she realizes her mistake she introduces Ramazan to her brother as her son in law Bayram since she was afraid of Hüsamettin's short-tempered character. Things get complicated when real Saban and Bayram come to the residence. Now Saban has to be Ramazan and Bayram has to be Saban. Meanwhile, a gulyabani (a ghoul from Turkish folklore) haunts the residence.