Help me find this old film

I watched this movie as a kid.. I was born in 88 this is probably 70s or 80s film. I believe it started off with picking up a hitchhiker. If I can remember correctly there were at least two people in the car one of them was a child. I believe they picked up a hitchhiker he had a really long fingernail that was pointed.. I can't really remember too much more I do remember there was a scene where a boy he was hiding in a barn behind bails of hay.

Hi.
I'm looking for an old black and white movie I saw way back in 1985.

It was obviously 1950's or 60's even. There were two sisters and one was shackled in the top of a barn, presumably she was insane or touched for some reason.

Vague I know but someone must know.