Sometimes horror isn’t just a boogeyman wielding a knife, a psycho pretending to be his mother or a monster munching on a coed’s throat, but something never intended to be scary, such as a botched performance, the fiery end of a career or a movie far worse than anyone could have imagined.

All can give you the willies.

So tomorrow night, if you’re in the mood for something completely different – a good fright that goes beyond the conventional horror movie – try thinking outside the casket and looking deeper into the video store. Indeed, sometimes what was never meant to be scary can be far scarier than what was designed to be scary.

Take Joan Crawford, for instance.

In 1967, Crawford, having hit rock bottom at age 63 but still eager to appear on-screen, starred as a circus ringmistress in “Berserk,” a stunning movie, in its own awful way, that dared to give Crawford a whip, an Edith Head leotard and a bouffant hairdo piled so high, it is amazing it never gets caught in the trapeze swinging above her.

As Monica Rivers – a grinning control freak unable to keep her monkeys or donkeys in line – Crawford’s great misfortune wasn’t just donning that wig, but that she had to speak this sort of dialogue: “You little slut – you miserable ingrate. This is a circus, not a charm school! We’ve eaten caviar and we’ve eaten sawdust!”

Crawford has been eating those words for 35 years.

In 1983, John Travolta, approaching what would prove to be a lengthy career slump, starred in “Staying Alive,” the damp yet colorful sequel to “Saturday Night Fever.” Just out on DVD, the film found the actor stepping right in it, so to speak, by sporting wrestler hair and baring a well-oiled chest that somehow got more attention than his high-kicking character, Tony Manero, a former disco king who ditched his white leisure suit for a birthday suit – and a chance to appear in the Broadway musical, “Satan’s Alley.”

Directed by Sylvester Stallone with the sort of numbing one-two punch you’d expect from a man who’s taken his share of blows to the head, the film’s interpretation of Hell is its best-selling point. It suggests that Satan is a softie, supporting a festive, musical environment in which leggings and eyeliner, wind machines and faux flames are not only encouraged but the order of the day.

Chilling stuff, for sure, but nothing compared to the worldwide fear Zsa Zsa Gabor ignited in 1958 when she co-starred in “Queen of Outer Space,” the sci-fi disaster that cast Eva’s sister as the only rational woman on the planet Venus. (So much for typecasting.) With Zsa Zsa unable – or unwilling – to conceal her Hungarian accent, the movie became sci-fi for the Eastern bloc, a ripe piece of trashovitch that suggested horror in its purest form.

A-list stars are hardly above spitting on their own graves and giving audiences nightmares, as Julia Roberts proved in 1996’s “Mary Reilly,” a movie that starred Roberts as plain old Mary Reilly, a grim maid whose glum life gets the kick it needs after she falls in love with John Malkovich’s Dr. Jekyll, a monster hiding a dirty secret. The movie, bad enough to raise the hair on a dog, initially was billed by the studio as Roberts’ bid for an Oscar nomination, which, had that happened, truly would have put the dog down.

Rock stars turned actors are almost always a reliable source for raising the sort of gut-wrenching scream that curls your toes, as Madonna did with spectacular results in 1993’s “Body of Evidence”; Prince before her in 1986’s “Under the Cherry Moon,” which nobody has yet to figure out; and Vanilla Ice in “Cool as Ice,” the 1991 debacle that soaked what was left of Mr. Ice’s career in liquid nitrogen.

Former child stars out of touch with reality often are great fun during Halloween – they offer both tricks and treats. Their lost, unhappy childhoods – well-publicized by them – are a boon when it comes to curdling one’s blood, especially if they should play characters hooked on booze and pills.

Patty Duke popped plenty and overdosed time and again in the unforgettable “Valley of the Dolls,” one of the best unintentional horror films ever, particularly when Duke fell to her knees in a wet alley and demanded that someone – anyone – bring her another doll.

Elizabeth Taylor had quite a doll collection of her own in “Boom!,” the 1968, Tennessee Williams-inspired shocker that starred the actress as Flora Goforth – yes, Flora Goforth – a woman whose rampant rages and mean mouth are far more toxic than anything in this week’s new video release, “Eight Legged Freaks.”

In the right frame of mind, all of the above movies – and so many others, too many to list here – are scary without ever meaning to be so. They’re also a lot of fun, proving that in a world where horror increasingly seems to be lurking just around the corner, the same is also true at your local video store.

Christopher Smith is the Bangor Daily News film critic. His reviews appear Mondays and Fridays in Style, Tuesdays on “NEWS CENTER at 5” and Thursdays on “NEWS CENTER at 5:30” on WLBZ 2 and WCSH 6. He can be reached at BDNFilm1@aol.com.