As we go to press, the spiritual leader of the Night People is looking for a sponsor. His name is Jean Shepherd, and he is (or was) the wee-hours d.j. of New York's WOR. "There's a great body of people who flower at night," according to Shepherd, "for night is the time people truly become individuals." Such folk, says he, "are embattled against the offcial, organized, righteous Day People who are completely bound by their switchboards and their red tape." Shaking the Day People from their smug complacency is the dearest joy of the Night People, and to this noble end, Shepherd and his night-owl listeners recently conspired in creating a mythical historical novel by a non-existent author. Bookstore clerks (archetypal Day People), when asked by Shepherd-inspired Night People for I, Libertine, by Frederick R. Ewing, consulted their all-powerful lists and haughtily informed the Night People that no such book or author existed. Their faith in Dayism was shattered when (a) requests for the tome poured in to bookstores in New York, Chicago, San Francisco, Miami, Paris and Helsinki; (b) a Pennsylvania d.j. interviewed British-accented author "Ewing" over the air; (c) the title cropped up in the Books-to-be-Published section of The New York Times Book Review; (d) the Catholic Legion of Decency banned it; (e) a confirmed Day Person (sub-species Librarian) found a card for the book in the index of the Philadelphia Public Library (in the corner of the card appeared the strange de-vice Excelsior, a favorite Shepherd battle-cry); and (f) 25,000 copies of the book itself miraculously appeared in book-stores everywhere. This crowning touch was the eleventh-hour brainstorm of late-listening publisher Ian Ballantine. As we understand it, Mr. B was fascinated by the hoax and recklessly confided to Shepherd that he'd publish the book if only someone would write it. Shepherd's crony, science-fictioneer Ted Sturgeon, said, "I'll write it!" - and he did, in 30 days. Shepherd, heavily disguised as Frederick R. Ewing, appears on the back cover of the hoax-that-became-reality, and al-though it unfortunately reads like the rush job it was, I, Libertine (Ballantine, 35c paper; $2 hardbound) is a memorable collectors' item and a tribute to that cult of night-blooming non-conformists in which PLAYBOY proudly claims membership. Maybe by the time we hit the newsstands Jean will have found a sym-pathetic sponsor. We hope so, but if not, let's raise a cry to restore the High Priest of Nightism to office. All together, now: Excelsior!