Of the fertile array of human relationships available to playwrights, few are so intriguing as that of master and servant. With the ever-present fears of punishment and rebellion, the opportunities for conflict are endless. Wendy Kesselman's "My Sister in This House," now playing at the Studio Theater, is an interesting treatment of that theme in a household steeped in repression.

The play, based on a sensational 1933 murder case in Le Mans, concerns four women: Madame Danzard, her daughter Isabelle and two sisters who work for them as domestics. From birth, housemaids Christine and Lea have been alone in the world, and their employment as domestic servants under the tyrannical Madame Danzard deepens their isolation.

Not long after they begin work at the Danzards, the housemaids run into trouble. Lea fails a few white- glove inspections, Christine's expert sewing is wrongly criticized. The sisters live in constant fear of the clucking and sometimes violent Madame Danzard (their neuroticism is reflected in increasingly intimate bedtime embraces), and when Lea accidentally burns an expensive silk blouse, the breaking point has been reached.

In the play's violent climax, Madame Danzard reveals her dangerous contempt for the servants: "You are dirt. You are scum." But only after being threatened with separation ("You'll never work with your sister again") do the sisters explode into the fury that lifelong terror can inspire.

The Studio Theater's production of "My Sister in This House" is highlighted by a multi-level set that is perfect for the claustrophobic confines of the Danzard household. And the acting, led by Sarah Marshall's Christine, is very strong.

Despite the production's virtues, however, a major fault lies in Mikel Lambert's portrayal of madame. Director Joy Zinoman depends on Lambert for so much of the comic relief that it becomes difficult to accept the maids' fear of what seems a ridiculous old woman.

Lambert bravely avoids giving a predictable "evil queen" characterization, but in doing so, she fails to make her household the stifling place of psychological torment that it must be. The slow pace of the show, though effective at times, can set programs rustling in long-delayed anticipation.

Nevertheless, "My Sister in This House" is an exciting representation of what can go wrong when the people upstairs trample on the folks downstairs who make their lifestyle possible.

MY SISTER IN THIS HOUSE -- At the Studio Theater through September 30.