When Thomas and Nancy Forbord moved back to Washington in 1975 after living abroad for five years, they almost lost their 4-year-old to something they call a "child-eater."

"Our children, who were 2 and 4 at the time, had seen TV only sporadically, and most of it was in Swahili," recalls Nancy Forbord. "Not having been around TV, we let them watch anything they wanted.

"Within six months I had lost contact with my son. He became extremely withdrawn and obsessed with watching certain programs. His life was concerned with the unreal, and he was doing a lot of role-playing of superheroes.

"He used to be very verbal, but now he was turning to TV. I found it frightening."

Forbord saw a public-service announcement of the Washington Association for Television and Children (WATCH). She began volunteer work with the group whose purpose is to improve children's programming and help parents make decisions on TV in the home.

Forbord discovered that her problem is a common one. The average American child of elementary-school age spends 3 1/2 hours a day watching television, according to the A.C. Nielsen Company.

(When third graders in a Connecticut school were asked to spell the word "relief," more than half spelled it R-O-L-A-I-D-S, as per the TV commercial, according to an Edward P. Morgan radio commentary.)

By the time a child has finished high school, he or she has spent 11,000 hours in classrooms and 15,000 hours watching television.

Forbord began limiting her children's viewing to one hour a day. "At first they protested, but then they got involved in other activities.

"Once the habit of always turning to the TV was broken, they found their own entertainment much more satisfying. Now they usually don't even watch an hour a day."

Now, as president of WATCH, Forbord appears Fridays on WJLA's "A.M. Washington" and suggests upcoming shows (on all channels) suitable for children.