LEAD: The proudly sophomoric comedy style of the Zucker-Abrahams-Zucker writing team, responsible for ''Airplane!,'' ''Top Secret!'' and now (with Pat Proft) ''The Naked Gun: From the Files of Police Squad!,'' is funniest when it's hardest to second-guess. But this time, in a scattershot detective parody that's a spinoff of the team's television series, things are relatively sane.

The proudly sophomoric comedy style of the Zucker-Abrahams-Zucker writing team, responsible for ''Airplane!,'' ''Top Secret!'' and now (with Pat Proft) ''The Naked Gun: From the Files of Police Squad!,'' is funniest when it's hardest to second-guess. But this time, in a scattershot detective parody that's a spinoff of the team's television series, things are relatively sane.

It will help if, while watching ''The Naked Gun'' at Embassy 1 or other neighborhood theaters, viewers can assume a mental age of about 14. The jokes will seem fresher that way, and they will also, much to the writers' credit, seem screamingly funny at times. Bathroom jokes, giddy repetition and calamitous pratfalls are the sine qua non of this kind of humor, but ''The Naked Gun'' gives such things an unexpected sophistication. Much of this can be attributed to the dapper presence of Leslie Nielsen who, as Lieut. Frank Drebin, manages to bring something heroic to the role of a perfectly oblivious fall guy.

First seen at a meeting of hostile world leaders in Beirut, Lebanon (''And don't ever let me catch you guys in America!'' he shouts to look-alikes representing Idi Amin, Yasir Arafat, Muammar el-Qaddafi and others), Drebin returns to Los Angeles and finds himself on the hunt for a diabolical businessman named Victor Ludwig (Ricardo Montalban). Drebin, who is more or less outsmarted by Ludwig's tank of expensive fighting fish, isn't much of a match for the man himself.

Nor can he keep up with Drebin's beautiful assistant, Jane Spencer (Priscilla Presley), who has a gift for the double entendre and an unfortunate habit of walking into things. ''The Naked Gun'' is so good-natured that it brings out the funny side of performers who, like Miss Presley, have never seemed to have much sense of humor in the past. Also in the cast, and equally well used, are George Kennedy as Drebin's friend and superior, Nancy Marchand as the Mayor of Los Angeles and Charlotte Zucker, who is David and Jerry Zucker's mother.

David Zucker, who directed ''The Naked Gun,'' has given it a cheerful, messy style that never quite matches the ebullience of the writing. But high spirits may be all that a film like this really needs.

One of the more inspired visual gags is the standard young-and-in-love montage that finds Mr. Nielsen and Miss Presley frolicking prettily together and experiencing quite a few physical mishaps themselves. This sequence ends with a small credit in its lower left-hand corner, making it suitable for use on MTV. Later on, once he and Miss Presley have begun their photogenic romance, she tells him, ''I'm a very lucky woman.'' ''So am I,'' Mr. Nielsen earnestly replies. It's impossible not to see that coming, but it's equally impossible not to laugh.

''The Naked Gun'' is rated PG-13 (''Special Parental Guidance for Those Younger Than 13''). It contains a number of innocently off-color jokes. Fighting Fish Into the Breach THE NAKED GUN: FROM THE FILES OF POLICE SQUAD!, directed by David Zucker; written by Jerry Zucker, Jim Abrahams, David Zucker and Pat Proft; director of photography, Robert Stevens; edited by Michael Jablow; music by Ira Newborn; production designer, John J. Lloyd; produced by Robert K. Weiss; released by Paramount Pictures. At Embassy 1, Broadway and 46th Street, and other theaters. Running time: 89 minutes. This film is rated PG-13. Lieut. Frank Drebin ... Leslie Nielsen Jane Spencer ... Priscilla Presley Victor Ludwig ... Ricardo Montalban Capt. Ed Hocken ... George Kennedy Mayor of Los Angeles ... Nancy Marchand Ludwig's secretary ... Charlotte Zucker