Is Faith Hill too good to be true? The 26-year-old newcomer behind the chart- topping country single ''Wild One'' has the wholesome beauty and angelic soprano that Nashville dreams are made of. She's got the Baptist upbringing and the requisite years in the church choir. Not to mention a proclivity for good ol' American values, the kind espoused in her favorite TV show, Little House on the Prairie. ''I cry every time I see one of those shows,'' she says. ''When I have kids, I want them to see 'em. They teach you so much about morals.'' It's enough to make the more jaded among us gag, except that there is the other Faith Hill. The one who sings the lyrics to ''Wild One'' with such conviction, you know she can relate to the rebellious teenager of the title. ''I wasn't a hoodlum or anything,'' she says, ''but I liked to get in trouble a little bit, to see how far I could go.'' Whatever the motivation, the result was four weeks at No. 1 on the Billboard country chart during January-a distinction no debut single by a female country singer has achieved since Connie Smith's ''Once a Day'' in 1964. For Hill, singing has been ''a therapy and a medicine. A way to touch on emotions that I couldn't get anywhere else.'' Raised in the pin dot of Star, Miss. (pop. 2,500), Audrey Faith Perry is the adopted daughter of Ted and Edna Perry, a blue-collar couple with two older sons. Admittedly single-minded about being a country singer (''almost since I started talking''), Hill dropped out of junior college and moved to Nashville at 19. ''I really believed I'd just get on the Grand Ole Opry stage, start singin', and be on a bus travelin' the next day.'' The only gig she landed was as a receptionist at singer Gary Morris' publishing company, and the Big Break wound up taking six years. A songwriter asked her to demo a song, then played it for an astonished Morris, who immediately pushed Hill out from behind her desk and into the care of high- powered manager Gary Borman (who handles Dwight Yoakam). The one glitch: a five-year marriage to music publisher Daniel Hill that was going nowhere. ''No beating or cheating occurred,'' she says. ''I just felt captured.'' The Nashville scuttlebutt: Hill left her husband for Scott Hendricks, the producer of her exceptionally solid album, Take Me As I Am. Hill doesn't deny the rumors but is reluctant to elaborate on their relationship. She's more forthcoming about visits with Leno and Letterman and a tour with Reba McEntire. Already, Nashville pundits are predicting Reba-like stardom for Hill, but don't expect any All About Eve back-stabbing. ''Reba's my idol,'' insists Hill. ''I want 20 years from now to feel like I made a difference in people's lives, the way she did with 'Is There Life Out There,' sending people back to college. It's truly amazing what music can do, isn't it?'' She's the living proof.