WITH a few more light bulbs and Fred MacMurray, Disney might have had a first-class kids' adventure in "The Journey of Natty Gann." But shadowy photography, meant to underscore the Depression- era setting, and some serious miscasting make this a middling, dreary-looking movie.

Newcomer Meredith Salenger and Ray Wise of "Swamp Thing" are a tepid team as a 1930s daughter and father separated by hard times. Salenger, in the title role, plays a resourceful tomboy who travels crosscountry in search of her father, who is forced to leave her in the care of a hotel clerk when he heads west for a scarce lumberjacking job.

On her way from Chicago to Seattle, she rides the rails through the mountains majestic, tags up with hobo John Cusak, and befriends a great, growling pit dog she names Wolf. The two travel through the yellow aspens and sow-dusted high country searching for her dad. She's rousted by paddywhackers, and Wolf is captured by dog-catchers. It's a typical animal adventure, stripped of its guts by an enfeebling if commendable effort to shield young viewers from violence and death.

Scatman Crothers brightens the screen, though, in his too-limited role as a Hooverville street vendor, and the new queen-sized Lainie Kazan is nicely jaded as a hard-nosed concierge.

The dog Jed, who plays Wolf wearing water- based makeup, is the best thing since Benji. He does great stunts -- jumping off water towers onto moving trains, for example. And he's completely convincing in his role as the wild dog tamed by the love of an innocent girl.

"Natty Gann" is, however, less suspenseful than "The Care Bears," and the ending is as predictable as "Rocky IV." But it certainly won't scare the kids. (At a recent showing, youngsters sat contentedly, easily following the simple plot. But a Cusak-Salenger kiss did cause a couple of "yeeuus" from the boys.)