1950sor 60s…possibly hitchcock…the hero is below a stage listening for which section of the stage above the bad guy is walking/standing so he can pull a rope for a trap door for that section sending the man to his death while the girl is hiding inside a podium on the stage
“Charade” (1963)
https://www.imdb.com/title/tt0056923/
Detailed plot description for “Charade” on Wikipedia:
https://en.wikipedia.org/wiki/Charade_(1963_film)
From Wikipedia:
“After another chase that ends in an empty theater, Reggie hides in the prompt box. Dyle discovers her and is about to shoot, when Adam activates a trapdoor beneath his feet, causing Dyle to fall to his death.”
Maybe Hitchcock’s Stage Fright.