The most frightening violence in "The Godfather" really wasn't gangland assassinations or shootouts -- it was the domestic violence between a wife-beater and his spouse. A 1976 survey found that at least 1.8 million American women are severely beaten in their homes every year, but for a long time this was a crime that dared not speak its name.

Increasingly, TV movies are showing willingness and ability to deal with once-hidden social problems like this. NBC aired a trailblazing movie on wife-beating, "Battered," with Karen Grassle and Mike Farrell, in the fall of 1978. Now comes an even more powerful, unsettling treatment of this subject: NBC's "The Burning Bed," tonight at 9 on Channel 4. The showing was scheduled to coincide with the beginning of Domestic Violence Awareness Week.

Farrah Fawcett, looking and acting anything but sex-kittenish, plays Francine Hughes, who in 1977 was found not guilty by reason of temporary insanity for slaying a husband who had beaten, abused and threatened her repeatedly for 13 nightmarish years. The title of the film, from the Faith McNulty book on which it is based, refers to the fact that one hellish night Hughes poured gasoline around the bed in which her husband was sleeping and set the house on fire.

Feminists were disappointed that the plea was temporary insanity and not self-defense; they thought the case would make a better rallying point if the jury ruled that Hughes was justified in striking back at the husband she genuinely believed might murder her. But the feminist thrust of the story comes through in the adaptation by Rose Leiman Goldemberg. The film does not endorse murder as a means of dealing with physical abuse; it depicts the plight of a woman who thought she had simply run out of alternatives.

Paul Le Mat plays Mickey Hughes, the deranged sadist whom Francine meets in 1963 and marries, unaware of his violent temper and obsessive jealousy. After the first beating, when the husband goes wild because he thought he saw his wife glance at another man, Mickey's mother Flossie (Grace Zabriskie) tries to rationalize her son's behavior with the worst, but probably most common, excuses in the world:

"I know he's jealous, but that's only natural." "It's your duty to stand by him." And, "It's not really so bad, is it?" A few years later, after the violence has escalated, the mother tells Francine, "A woman's gotta take the bitter with the sweet, you know." But it should never get this bitter.

Fawcett, who starred for years on "Charlie's Angels," no longer has to prove she can really act, because she did that in the TV movie "Murder in Texas" in 1981. She gives a strenuous and superb performance. Le Mat, also cast against type, reveals not only the vicious cunning but also the pathos of a man who would strike out with violence one moment and fawningly beg for forgiveness the next.

Because it deals with violence, "Burning Bed" includes depicted violence. Sometimes we just hear the sounds of a fight while the camera focuses on the outside of the house or on the faces of the couple's three terrified children. But some of the fights are recreated on camera -- not as graphically as they were described in the book, but as graphically as anyone would want. Fawcett and Le Mat go through hell for us in presenting this horror story. One has to believe it may serve a good purpose.

As in most such TV films, the story is told in flashback. It opens with Francine meeting her lawyer in jail after her husband has died, then goes back to the beginning of their courtship. The film concludes with the trial and with a reenactment of the day on which Francine Hughes finally found a way to fight back. Director Robert Greenwald handles this essentially awkward structure pretty well, and he is in full command when it comes to making the violence truly chilling.

For years it has been a mistake to judge a TV season solely by the weekly shows that bubble mindlessly by night after night. This year the networks will air more original TV movies than ever, having learned that theatrical films can cost more to buy and deliver smaller audiences because of previous exposure on cable and cassettes. Most of the TV movies, like most weekly shows, will be frothy and dumb, but some will try to deal honestly with topics of our time. "The Burning Bed" obviously fits into the latter category.

"The Burning Bed" can join the proud ranks of "Adam," "Something About Amelia," "The Day After," and the recent "Heartsounds" -- serious and intelligent television about matters of intimacy and universal concern. 'Wonderworks'

"Wonderworks," public TV's new family entertainment series, began last week with a dramatization of Booker T. Washington's early years and continues tonight in a much more whimsical vein with "How to Be a Perfect Person in Just Three Days," at 8 on Channel 26 and the Maryland public TV stations.

The one-hour comedy with a message, written by Bruce Harmon and directed by Joan Micklin Silver ("Hester Street," "Chilly Scenes of Winter"), chronicles not the decline but a great many falls in the life of Milo Crimpley, a 12-year-old klutz with a knack for walking into trees, spilling food and dropping whatever anyone is foolish enough to let him hold. Milo decides something must be done, and fortunately he is plastered in the face by an advertising flyer that ballyhoos a certain Dr. K. Pinkerton Silverfish, specialist in the not-so-perfect science of perfectology.

Visited by the boy in his Rube Goldberg lair, Dr. Silverfish promises Milo he will achieve perfection if he follows three instructions, which are doled out a day at a time. The first is that he walk around all day with a stalk of broccoli around his neck, the second that he fast for 24 hours, the third that he attempt to do something he's never done before and never thought he could do.

From the broccoli incident he learns self-confidence and freedom from embarrassment, from the one-day diet he learns willpower, and so on. The lessons are imparted with a light touch that is never preachy, although Silver's direction seems too dry and precious and the dialogue suffers from a too-cute children's storybook ring.

The cast, however, is top-notch. As Milo, Ilan Mitchell-Smith is a winsome lad with a helium voice. Wallace Shawn is up to his very old tricks as the mildly mad doctor, but most of them still work. Silver has found the best use for Hermione Gingold -- as Miss Sandwich, the imperious schoolteacher -- in years. And Kate McGregor-Stewart maintains a disarming look of pained resignation as Milo's suffering mom.

Essentially, this edition of "Wonderworks" is no better than one of the best "ABC Afterschool Specials," but there's certainly no shame in being that good.