Adults might not have succeeded quite yet in appropriating Halloween all for themselves, but they seem to be getting closer every year.

According to the National Retail Federation, consumers are expected to spend nearly $5 billion – up from $3.4 million last year – on Halloween costumes, candy, decorations and assorted party paraphernalia by the time the holiday rolls around next Tuesday.

With more than 50 million people hosting or attending ghoulish get-togethers, Halloween has become the nation’s third biggest adult party day, after New Year’s and Super Bowl Sunday.

Marlene “Bunni” Paulette and her husband, Bob, don’t need national sales figures to track the evolution of Halloween from a single evening of fun for kids into an adult dress-up phenomenon that can last a couple of weeks or more, a season unto itself.

The couple did have children in mind, of course, when they first converted the den of their Bangor home into The Castle of Costumes in 1991. But within a couple of years, their adult clientele had grown so big that they decided to get out of kids-costumes completely.

“Oh, yes, I’d say adults have taken over Halloween,” Bob said Monday morning as he and Bunni prepared for their very busy days ahead. “There were already lots of parties this past weekend, and there will be lots more next weekend, too.”

As usual at this time of year, the Paulettes’ phone starts ringing early in the morning and continues until well into the night.

“We get plenty of weird calls, too,” said Bob, “like people wanting to know if we have a potato costume, or any kind of vegetable. One guy called last week and asked if we had a dollar-bill costume. Turns out his wife is dressing as an ATM machine.”

The Grim Reaper and the mummy are as popular as ever with adult revelers, the Paulettes said, although demand for Elvira, the sexy vamp, has ebbed in recent years.

“Elvira’s worn out now, but we’ve got one that’s really a riot,” Bob said as he pulled from behind the counter a flesh-colored body suit of exaggeratedly saggy female proportions, tassels included. “This is the ‘Fat Stripper,’ but you’ve got to know the person you show it to. Some people might be offended.”

The Paulettes believe adults have seized on Halloween in the last decade or so simply as a way to guiltlessly escape the stresses of everyday life.

“With the economy, the war, the price of gas and everything else,” Bunni said, “it seems like adults just want to forget for a while and go out and have some fun.”

People like Phil Goody from Bradley, for example. He visited the shop Monday in search of an Uncle Fester costume – from “The Addams Family” TV show – for the fifth annual Halloween bash he’s hosting at his barn this weekend. Goody is expecting about 120 people at the party, which will include a bonfire and a live band.

“I’ve gone as a woman for the last two years, so my wife said I had to be a man this year,” said Goody, who plans to spend about $700 for the shindig and will even shave his head for his Uncle Fester role.

Not only are adults increasingly taking over Halloween as their own, the holiday seems to be going to the dogs as well: Nearly four million people will buy costumes for their pets this year.

Now that’s a frightening thought.