When I was a small child I saw a late night movie about some big house and if someone slept in one specific room, they disappeared. There was only door in or out. The window was a long way down that would send a person onto crashing waves.
A man and woman wanted to figure out the mystery and I believe he planned to stay the night in the room.
That is all I remember, other than it had a logical explanation and not a supernatural one. I’ve wanted to see it again for the longest time but haven’t been able to find it.
Maybe one of the versions of a German story “Geheimnis des blauen Zimmers” (usually translated as “Murder/Secret in the Blue Room”) by Arnold Lippschütz:
https://www.imdb.com/title/tt0022929/?ref_=nm_flmg_wr_7 (Germany, 1932)
https://www.imdb.com/title/tt0170849/?ref_=nm_flmg_wr_6 (Czechoslovakia, 1933)
https://www.imdb.com/title/tt0024538/?ref_=nm_flmg_wr_4 (USA, 1933)
https://www.imdb.com/title/tt0030455/?ref_=nm_flmg_wr_2 (USA, 1938)
https://www.imdb.com/title/tt0037100/?ref_=kw_li_tt (USA, 1944)