Zelda Rubinstein: Actress best known for playing the eccentric medium in 'Poltergeist'

Zelda Rubinstein will be best remembered for her role as the eccentric medium attempting to free a home of demonic influences in Tobe Hooper's horror film Poltergeist (1982). Rubenstein was 4ft 3in tall, and the original script, co-written by Steven Spielberg, who was also a producer of the film, was conceived with the role of psychic Tangina Barrons expressly written to be played by a little person.

"I thought it would be neat to show that someone's size has nothing to do with her psychic powers," said Spielberg. "Good things can come in little packages, and that's certainly true of Zelda." The film moves into a higher gear when Rubinstein appears, her child-like voice and eerie calm allowing for touches of welcome humour. Touring the house after a young girl has been sucked into her bedroom closet and disappeared, she asks, "Do y'all mind hanging back? You're jamming my frequencies."

Besides her performances in films and on television, Rubinstein was a noted activist for the rights of little people (the term she preferred). She also campaigned for Aids education and greater public awareness of the disease in 1984, when it was courageous to do so. She appeared as a mother figure in a series of commercials aimed at gay men, and said later that she did "pay a price, career-wise".

Rubenstein did not start acting until she was nearly 50. She was born in Pittsburgh in 1933, her lack of height due to a deficiency of the anterior pituitary gland, which produces growth hormone. She described herself as "the only one different in appearance" in her family. Educated at the University of Pittsburgh and the University of California, Berkeley, she became a laboratory technician. After working for several years in London, she decided to change careers.

"I had to do something creative," she said. "I felt I was sabotaging myself... I had no idea what I would do next, but I knew it would involve advocacy for those people who were in danger of being disenfranchised."

Her screen debut was not auspicious, playing an actress appearing as a Munchkin in The Wizard of Oz in the tasteless farce starring Chevy Chase, Under the Rainbow (1981). The following year, her bravura display as Tangina in Poltergeist, ordering hostile spirits to "go into the night" before declaring, "This house is clean!", received an overwhelmingly favourable response, The Washington Post hailing her performance as one of the best by an actress that year.

Rubinstein reprised her role as Tangina in two sequels, Poltergeist II: The Other Side (1986), and Poltergeist III (1988), and she later made guest appearances as a seer in the television spin-off, Poltergeist: The Legacy (1996). She played a mental patient in Frances (1982), in which Jessica Lange starred as Frances Farmer, the tragic self-destructive actress, and she had the small role of an organist in John Hughes' Sixteen Candles (1984). Many of her other films were low-budget independent productions, including Anguish (1987), Teen Witch (1989) as another medium, National Lampoon's Last Resort (1994), and Little Witches (1996).

She provided voice-overs for television's The Flintstones and appeared on many television shows including Matt Houston (1983), Faerie Tale Theatre (1987), Mr Belvedere (1990) and Tales from the Crypt (1992). She had a recurring role as a sheriff's assistant in the series Picket Fences (1992-94), and for several years she narrated the series Scariest Places on Earth (2000-06). Her last film role was a cameo in the horror film Behind the Mask: The Rise of Leslie Vernon (2007).

In 1981, Rubenstein helped found the Michael Dunn Memorial Repertory Theater, in which the tallest performer was 4ft 6in; Dunn was the small actor who achieved recognition in Ship of Fools (1965). "Little people are societally handicapped," Rubinstein observed. "They have about two minutes to present themselves as equals – and if they don't take advantage of that chance, then people fall back on the common assumption that 'less' is less."

Tom Vallance

Zelda Rubinstein, actress: born Pittsburgh, Pennsylvania 29 May 1933; died Los Angeles, California 27 January 2010.