Can someone help me find out if this is the movie I saw?

That's the one! Olivia de Havilland was just released from a mental institution. While walking in an empty lot, she hears a woman crying out for help, but doesn't see anyone around. No one will believe her story because they all believe her to be "crazy". She finally sees a woman buried alive (her husband put her there) and is able to get help to have the woman dug up (still alive). The final scene is the woman being dug up from the ground while people are watching, now realizing Olivia is not crazy, and the woman's husband (who tried to kill her) is hauled off to jail. There's a real "Carrie" moment (before Carrie!) when the woman in the ground reaches up and grabs Olivia's hand. Olivia screams and screams, hence the title. One of the best movies EVER -- super scary!

I was about 6 years old, walked in the room and just in time to hear a woman screaming/moaning and hauling herself up out of the ground and falling over while people stand around with their jaws hanging open. All the years afterwards, I thought the movie was about a zombie or ghost coming back from the dead. That scene out of context is actually scarier than if you knew what happened before. Gave me nightmares for years afterwards and took forever to be able to see it again. It's an excellent movie. I can't understand why it is not available on DVD.

Now available free on YouTube.

https://www.youtube.com/watch?v=CrGy9VSf6fs

"Cum Grano Salis"