THE ectoplasm that bounces about the Stygian-black stage of the Lyceum Theater is all man-made, although not until the very end of ''A Little Like Magic'' do you see a full, normal human being. This puppet show, which opened yesterday, is something the like of which you may never have seen. It comes to us from Canada, the home of the puppet troupe Famous People Players.

Here are a pair of dancing feet, a hat and hands - identifiably human but disembodied. Now the insistently pervasive music shifts to Liberace, and a very large Liberace - a caricature - pounds a piano that is also a caricature. It all emerges from the dark. There are mammoth chickens sawing fiddles to a Celtic tune, and scenery of a desolate sort floats in as the backdrop for the enactment of ''The Sorcerer's Apprentice.'' Now our attention is riveted by country singers and rock stars as well as animals struggling to the death to the strains of Mussorgsky.

Black light is the secret of this viewer-friendly, iridescent spectacle that drenches the senses in sight and sound for almost two hours. It is something for the kids and also for grown-ups, the sort who enjoy a night off from entertainment that the audience has to work at.

''Magic'' is clever, colorful and cute. The colors are loud and so is the music. Sometimes, it feels as though you are sitting through some gigantic music video, with the selections ranging from Saint-Saens to Kenny Rogers by way of Cole Porter, Rodgers and Hammerstein, George M. Cohan and Stevie Wonder. For all the diversity of melody, the effect is still more a la Disney than Carnegie Hall. Everything has a kind of Technicolor brightness, the music as well as the puppets - and the show, conceived and directed by Diane Lynn Dupuy, is attractively inventive.

The black void that is the background makes the painted objects appear even more vivid than they would otherwise. Dinosaur skeletons, birds, shoes - everything assumes a comic, sprightly air. The finale, a rousing medley of Broadway songs, is followed by a genial curtain call that lets the audience in on how the whole thing is put together.

There are times that ''A Little Like Magic'' does seem like magic: the magic of theater, the magic of diversion, the magic that impels one to say, ''That's entertainment.'' SORCERY'S APPRENTICES A LITTLE LIKE MAGIC, conceived and directed by Diane Lynn Dupuy; visual art effects by Mary C. Thornton; lighting by Ken Billington; sound by Lewis Mead; production supervisor, Sam Ellis. Presented by the Famous People Players. At the Lyceum, 149 West 45th Street. WITH: Darlene Arsenault, Michelle Busby, Sandra Ciccone, Charlene Clarke, Annastasia Danyliw, Benny D'Onofrio, Any Fitzpatrick, Kim Hansen, Greg Kozak, Debbie Lim, Renato Marulli, Debbie Rossen, Mary Thompson, Neil Thompson and Lenny Turner.

Photo of Liberace caricature