Talk about a hard act to follow. Kathleen Chalfant won an OBIE, a Lortel Award, a Drama Desk Award and Outer Critics Circle Awards for her role in Margaret Edson's Pulitzer winning drama, Wit. But all great things come to an end, and Chalfant will leave the Pulitzer Prize-winning drama, as scheduled on Aug. 8.

Filling her enormous shoes, beginning Aug. 10, will be Judith Light, best known for her eight years on ABC-TV's "Who's The Boss," two of Light's television co-stars: Tony Danza (The Iceman Cometh) and Danny Pintauro (The Velocity of Gary) recently treaded the New York boards. Light's stage credits include playing the maid in a 1975 Broadway mounting of Ibsen's A Doll's House (opposite Liv Ullman and Sam Waterston), as well as the Broadway play Herzl.

Also being added to the cast on August 10, are William Cain (The Heiress), Sally Parrish (The English Teachers) and Grant Show ("Melrose Place") in the roles of Dr. Harvey Kelikian, Dr. E.M. Ashford and Dr. Jason Posner, respectively.

Wit, playing at the Union Square Theatre, tells of a strict college poetry professor brought low -- to humility and humanity -- by her bout with ovarian cancer. A national tour of the show is planned for January September 2000, but no casting has been announced.

For tickets and information on Wit, directed by Derek Jones, call (212) 307-4100. -- By Sean McGrath