"Once inside the attraction, you will be subjected to intense audio and lighting effects, low visibility, strobe lights, water and fog. You should not enter if you are pregnant, are claustrophobic, are prone to seizures or have heart and/or respiratory problems... THERE ARE NO REFUNDS! ENTER AT YOUR OWN RISK!"

-- warning found at NightshadeManor.com

In the "Haunted Attraction" industry, web sites are nothing new: Just about every haunted house, hayride and Halloween trail in the country is draped with artificial cobwebs inhabited by prop or mechanical spiders.

A ghoulish family awaits guests at the Nightshade Manor haunted attraction.

Visitors can learn a little anatomy during their tour of attractions at Nightshade Manor.

But Web sites -- the computer kind -- are an increasingly important part of Halloween, which has become a $7 billion-a-year industry, according to the Haunted House Association and the International Association of Haunted Attractions, the two trade groups that represent the "hauntrepreneurs" who operate the 2,000-plus "haunted attractions" found in the U.S. each October.

Robert Thomson, 34, a human resources software consultant, is a haunt hobbyist who this year introduced hauntedmidsouth.com, a Web site that reviews the major haunted attractions in the Memphis area, from the Agricenter Corn Maze to Nightshade Manor Haunted House to the Hauntedweb of Horrors sites operated as a fundraiser for Youth Villages, to name just a few.

Thomson uses a "skull" rating system to grade the attractions in eight categories, such as "Special Effects," "Gore Factor" (is the attraction suitable for kids?) and "Value" (do customers get their money's worth?).

For example, in his review of "Hauntedweb of Horrors -- Tormented" at 700 N. Germantown Pkwy., Thomson gives the "Gore Factor" three skulls, writing that even the attraction's theme -- "an asylum run by a mad doctor who does experiments on the patients, then casts the body parts out back in the swamp, only to have those parts collected by the inbred cannibal swamp-dwellers" -- promises "a pretty adult haunt."

"Every single one of these places are all about entertaining people," said Thomson, who prefers live haunted attractions to horror movies. "Some are more extreme, and some are a little more family-friendly.

"My favorite thing is not necessarily the scaring, it's the visual effects. It's almost like a magic show, the illusions they produce."

Thomson's Web site is motivated by his longtime love for haunted houses as entertainment. But even the organizers of most area haunts are in it for enjoyment more than money. Like the song said, ghouls just want to have fun.

"Most haunters have other jobs," said Kevin Gaiman, who partners with Jeff Hanover to operate the 5,000-square-foot Nightshade Manor at 1301 Heistan Place (just east of Bellevue, and a few blocks south of Central), the only major "haunt" still in the Memphis city limits. (It benefits the Mid-South Food Bank -- admission is $12, or $10 with donation of two nonperishable food items.)

"For us, this is a like a show, a theater production," said Gaiman, 48, who works for Hilton Corp. in his non-ghostly life. "We're putting on a show, with the house lights, the staging, the makeup, the costumes, the actors, everything."

Gaiman said preparing each season's show is "a yearlong project -- I'm obsessed." After the last Nightshade Manor tour on Halloween night, Gaiman and Hanover will begin making plans for 2010. They'll likely purchase some spooky new effects and animatronics at the 15th annual TransWorld Haunt & Attractions trade show in March in St. Louis, the nation's largest weekend gore store, where vendors market the latest wrinkles (and wounds and scars) in scare technology.