Halloween may bring out the ghost, ghouls, and goblins in all of us, but it is the grown-ups who seem to be flocking to fright night in droves.

No longer relegated to a one-day celebration on Oct. 31, Halloween is now its own spooktacular season as pumpkins and skeletons start haunting store shelves after Labor Day. When all of the cobwebs are dusted off, a whopping $5 billion will have been spent on the holiday in 2007, with the average American shelling out $64.82 on costumes, candy, and decorations. That’s up nearly $6 from last year, according to the National Retail Federation. Overall, Halloween is the second-biggest holiday behind Christmas in home-decorating sales, and the sixth-biggest retail holiday for overall sales.

Trendspotters say Halloween-crazed adults have been driving much of that spending for the past five years, although no one knows why grown-ups love this holiday so much. Some muse that Halloween’s popularity is part of the post-September 11 nesting craze. Richard Laermer, author of 2011: Trendspotting for the Next Decade, says fantasy is absolutely crucial for stressed-out adults right now. “The idea of pretending is something that we all just realized is not only possible, but absolutely essential,” Laermer says.

Others say grown-ups simply embrace Halloween to have some much-needed fun: “Halloween is a holiday that brings out the kid in all of us,” says Sam Calagione, owner of «investing.businessweek.com» in Milton, Del. “It allows us to be mischievous, adventurous, and creative.” Talk about getting into the holiday spirit: This year Dogfish produced 35,000 cases of its Punkin Ale beer, which is brewed with pumpkin meat and brown sugar. Tricked-Out Treats

Candymakers, meanwhile, are creating sophisticated indulgences that go well beyond the standard fare of candy corn. At chocolate giant Godiva, a unit of Campbell Soup («www.businessweek.com»), impulse shoppers can gorge, for $4.50 each, on a fresh strawberry dipped in white chocolate and designed to look like a ghost. “Adults seem to love the fun aspects of Halloween, even more than children,” says Erica Lapidus, Godiva’s head of public relations and promotion.

As for other treats, the Great Pumpkin’s got nothing on the $50 pumpkin shells filled with milk or dark chocolate-covered caramelized almonds available at La Maison du Chocolat, a high-end French chocolatier. But you’ll have to go on a witch hunt to find other boxed chocolates whimsically decorated with pumpkins and owls. La Maison du Chocolat’s store in New York’s Rockefeller Center sold out of all 400 of these molded $20 treats in two weeks, according to Nora Hovanesian-Mann, La Maison du Chocolat’s director of New York operations. Home and Body Decor

The Halloween-induced sugar high seems to be fueling a festive spirit, too, as more adults go wild with outlandish decor. Some of the best-selling decorations at retailing giant Target («www.businessweek.com») include a life-size witch that lights up and delivers spooky shrieks. Tombstones, meanwhile, are a big hit at «investing.businessweek.com», another retail chain. “They are very affordable, and they don’t take up a lot of space,” says Bill Furtkevic, Party City’s vice-president of marketing.

Godiva’s research shows that two-thirds of its customers are planning Halloween parties this year, up from 50% in 2006.

No Halloween party is complete without a costume, of course. Retailers say pirate getups are among the biggest sellers this year for men. “Our most popular costume is Captain Jack Sparrow,” Furtkevic says of the character from Walt Disney’s («www.businessweek.com») Pirates of the Caribbean films. “The guys, at least, want to be Johnny Depp,” he says. Women, meanwhile, are buzzing to be honeybees and ladybugs, Furtkevic adds.

At Target men are flocking to animal costumes, including gorillas, while women are buying Wonder Woman and queen costumes, according to Lena Michaud, a Target spokeswoman.

One of those pirates, superheroes, or furry creatures might even show up at your office on Oct. 31: According to a new survey by «investing.businessweek.com», 27% of employees dress up in costume. Your boss in a gorilla suit? Now that’s a scary prospect.

«images.businessweek.com» to see a bagful of Halloween goodies for grown-ups.

May 29, 2007 — FIRST, let me tell you that I am in a terrible mood today. So, trust me, this column is going to be great.

OK, you deserve an explanation of that apparent contradiction. (And despite the fact that I’d rather tell you off, I will give it to you.)

A Rice University professor says that being in a bad mood is actually a good thing.

How’s that again?

Associate Professor Jing Zhou contends that perennially happy people don’t make the best employees.

They aren’t as productive and creative, the prof contends, as people who are sometimes in a foul mood.

They don’t have, as they say in the razor business, the edge.

So my bad mood, it follows, is going to lead to one helluva column. And since I’m feeling particularly nasty I really don’t care if you agree with me.

But here goes with some of the news that’s been piling up in my briefcase, which I decided to clean over the holiday weekend. (Yep, it was that good.)

* A small inner city New Jersey company that sells liquefied worm poop in recycled soda bottles is being sued by Scotts Miracle-Gro, the lawn company.

Scotts contends that the liquid worm excrement bottled by Trenton, N.J.-based TerraCycle is being unfairly marketed as better than artificial fertilizer.

Hey, I got some questions and don’t give me any crap.

How do they collect the little guys’ dung? And is there any chance some of those bottles could get on my supermarket’s shelf?

If you ask me Coke already has too many flavors.

* A workplace expert says there are still “at least” five chief executives at Fortune 500 companies who are gay and still in the closet.

“Some are married, some are divorced,” says expert Kirk Snyder who was trying to hook his book “The G Quotient: Why Gay Executives Are Excelling as Leaders” to the petticoat of Lord John Browne, who resigned recently as head of BP.

This, of course, is a nice little fact to know in case you ever get drunk enough to actually discuss a stupid issue like that.

But I’d prefer to know if there are five such CEOs who can be trusted. More gay than honest CEOs? It could be a close(t) contest.

* Last month the FBI arrested John P. Tomkins, a 42-year old machinist and Post Office worker for sending pipe bombs and mailing more than a dozen threatening letters to investment firms. Authorities said he wanted the firms to drive up the price of two small companies he had invested in.

He threatened employees and their families if the price of his stocks didn’t rise.

This was probably before Jim Cramer explained that you could accomplish the same thing with one phone call to a certain financial TV station.

Hey, but give the P.O. guy some points for loyalty. At least he didn’t FedEx the threats.

* Meanwhile, the maker of Snickers and Mars candy bars recently agreed it would no longer pitch its main products to children under 12, starting at year’s end.

This could be part of a trend.

Purina might want to only sell dog food to cat owners, and vice versa. And Mercedes could start marketing its cars to 12-year-olds. No reason adults should be tempted.

* A Charles Schwab survey shows that boys believe they will earn $173,000 a year and girls $114,200 when they grow up.

And I wonder what their expectations are about postmarital sex?

It seems like they might aim a little high on that issue as well.

john crudele@nypost.com

A House of Lords committee is to carry out an inquiry into the potential impact of the EU reform treaty, ahead of the forthcoming parliamentary debate on its ratification.

The Lords’ European Union committee will oversee seven sub-committees taking evidence and questioning witnesses in detail on the issues covered by the treaty, which replaces the failed EU constitution, and is due to be signed by the prime minister in December.

The treaty is expected to be the subject of fierce debate parliament for as long as three months in the New Year before a vote on ratification.

Mr Brown is resisting Conservative calls for a referendum on the treaty, insisting that MPs should decide whether the UK signs up.

Lord Bowness, a member of the Lords sub-committee which will look at the treaty’s provisions on freedom, justice and security, said: “The inquiry by our sub-committee is just part of a wider detailed inquiry. We aim to provide a detailed, comprehensive analysis of the important changes brought in by the treaty and how they would affect Britain.

“Our final report, when published, will give parliamentarians and others an in-depth assessment of what the treaty would mean for us.”