Fletcher is returning this weekend to the institution where the movie was made in 1975, the Oregon State Hospital in Salem, the Statesman Journal reported.
The hospital, long under fire for inadequate programs and crumbling facilities, has been rebuilt in recent years. Fletcher is attending the opening of its Museum of Mental Health.
The movie is based on the novel by Oregon writer Ken Kesey. It centers on the struggle between the steely Nurse Ratched and Jack Nicholson's scheming character, Randall McMurphy, who eventually gets a lobotomy for leading a rebellion among the prisoners on his ward.
"I was really shocked in those scenes where I was actually so cruel," Fletcher said.
In 1975, Dr. Dean Brooks, then the superintendent, opened the campus to the cast and crew. Fletcher said she was in the city 11 weeks, filming six days a week. He and Fletcher have stayed in touch — they talk by phone each July 22, their common birthday.
Brooks recalls the actress as being nothing like the character: "I have found her to be angelic."
Fletcher, whose parents are deaf, took time out from filming to visit students at the Oregon School for the Deaf, he said. He said he's admired how she doted on her parents and cared for them as they aged, and how she dropped everything to spend time with a dying friend in London.
Fletcher said better known actresses turned down the role, and it wasn't until she saw the film for the first time with an audience, in Chicago, that she was convinced she pulled it off.
In scene where McMurphy throws Nurse Ratched against the wall and chokes her in a fit of rage, she said, "they all stood up and cheered in the theater and were stomping their feet. That got to me. I realized, 'Hey, I created a real villain here.'"