Bette Davis and Gena Rowlands may be as formidable as any actresses on earth, but that doesn't mean they can hold one's interest while they spend two hours waiting for a play to be written. "Strangers: The Story of a Mother and Daughter," a CBS movie airing at 9 p.m. tomorrow on Channel 9, doesn't even qualify as a sensitivity greeting card for Mother's Day, unless Lady Macbeth happens to be your mom.

Michael de Guzman's script lurches amateurishly between a high howl and a low hoot in this perfectly dreadful brawl between a stern New England mother and the daughter who mysteriously, after 21 years away, drops in again-but only because she has one of those chic terminal diseases people on television are always getting. This malady can be diagnosed from the first "cough, cough."

The death notice is the pretext for the visit, and it's a natural reaction to wish the daughter ahd been content just to drop mother a note: "having wonderful terminal disease," and so on. Instead, the two spend a large part of the first hour of the movie fighting over who should feel more guilty about what who did to whom.

"I know how old you are," says Rowlands. "I know how old YOU are," says Davis. It goes on like that Davis says, "You took and you took and you took and you never gave anything back," and, later, really revved up, "You selfish bitch! Taking, taking, always taking!"

They reconcile and regroup, only to start a new row. The film is not so much a two-character drama as a pair of monologues that never intersect; it thrashes around like a hook trout. Obviously the actresses read the script, saw its opportunities for histrionics and leaped at the allegedly meaty roles. "There's more meat in a cheese omelette.

It isn't as if we need someone to make bad Ingmar Bergman movies; Ingmar Bergman makes them himself now. And director Milton Katselas apparently gave the actresses his word there would be no close-ups, so all of this guilt-schlepping occurs in the dim bye-and-bye.

People such as Bette Davis (and Katharine Hepburn) are supposed to be in a royal class that protects them from criticism, but Davis looks and acts like a self-parody here. Of all the ironies, she is beginning to resemble her old costar, Claude Rains-in his later years. When she slams the door and cries for the camera, she shimmies about as if her big toe were stuck in a light socket.

Rowlands, so outstanding in ABC's "A Question of Love" last November, can't do much with her character either, and when the writer hauls out an unfinished jigsaw puzzle as a metaphor for life-oh, brother, and oh, mother! Which way to Fantasy Island? CAPTION: Picture, Gena Rowlands and Bette Davis in CBS' "Strangers"