CBS lopes from the sweeps to the sleeps tonight with one of the dreariest TV movies of the year, "Svengali," a two-hour nap at 9 on Channel 9. The casting of Peter O'Toole TV Preview and Jodie Foster, as a 50-year-old vocal coach and his 22-year-old pupil, proves embarrassing for both, and the drama in which they are involved is hopelessly pointless and protracted.

In the script by Frank Cucci, the O'Toole character doesn't exactly function as a Svengali anyway. His pupil does become dependent on him, but he doesn't exercise any particularly devastating power over her. It's really the other way around. In the second hour comes the groggy moment of truth: She says, "I want to go to bed with you." He says, "Lots of people do." She says, "I'm special."

Director Anthony Harvey seems to be striving for soporifics. He opens the film with Foster under hypnosis and follows that with a sloowww pan across a room. Foster does not give a performance worthy of the word, and she's gone unattractively puffy, something like Tatum O'Neal. She looks even more ordinary than she sings. The idea that this clodhopping pudge would become a smash sensation overnight is too preposterous even for a society in which such wretched things do indeed happen.

O'Toole shows the role and the film the proper contempt, but after a while even he can't remain Above It All. Words roll around in his mouth like mints, and the character never really does ignite. But considered in conjunction with O'Toole's happily madcap turn in "My Favorite Year," O'Toole's work here suggests the time is ripe for the actor to star in a revival of "Twentieth Century." What a high time he could have roaring around as the magnificent egomaniac Oscar Jaffe. Finding him a leading lady would be a challenge, but at least Foster will be out of consideration. To most decent, God-fearing people, she has probably lost her charm, and can now melt quietly back into history.