Jennie Gilroy didn't have her own black, horse-drawn hearse.

So she spent four months building one, complete with red velvet curtains, side glass windows, eerie lights and a talking skeleton for a coachman. She thinks the shiny carriage for the dead fits well with her graveyard and Gothic church, the latter actually a tall facade that obscures her Elizabeth Drive home in east Petaluma.

The regular house had to disappear, she said, so that on Halloween night little children can wonder if they're visiting a place that's not only spooky but also magical.

"I wanted to give them the same feeling that they get when they go to Disneyland," said Gilroy, a hairdresser and Petaluma High grad.

Her home's makeover may be extreme but it's hardly unique. Around Sonoma County, people are transforming their front yards into cemeteries and scary haunts, decked out with animatronic characters, smoke machines, strobe lights and sound effects aimed at creeping out both young and old.

Halloween is no longer merely a night of trick-or-treating with a jack-o'-lantern lighting the front porch. The holiday has become second only to Christmas for the money spent celebrating it.

Americans will part with an estimated $6.9 billion this Halloween season, according to the National Retail Federation. That includes nearly $2 billion on home decorations, $2 billion on candy and $2.6 billion on costumes — of which $330 million is just for dressing up pets.

While total spending is expected to decline about 14 percent from last year, the average amount spent by revelers has still increased nearly 55 percent since 2005.

For the house haunters, all the skulls and bones and spooky trappings are supposed to help children experience the fun of Halloween, much as these adults said they did when they were young. So much the better if the grown-ups get to have some fun, too.

"It's kind of my one excuse to be a kid again and to work with my hands," said Rick Nelson, a Rohnert Park resident who works as an employment recruiter in San Francisco.

Among the decorations at their Santa Cruz Way home, Nelson and his wife Erin have added "snakes" made from flexible pipe insulation. The hose-like strips of insulation were spray painted through a window screen fabric to create a reptilian look. Two golf tees then were added to each snake for fangs.

Getting everything together can take months.

"We start planning and shopping in the summer," said Nicole Griffith, standing outside her Pinot Noir Way home in Windsor.

Behind her, eight-foot-wide spiders hung along the second-story walls, while a pirate's skeleton swung from the front porch.

On Halloween, she said, trick-or-treaters will pass up a driveway featuring zombies, strobe lights, fog machines and about 2,000 plastic spiders and centipedes spread over the concrete.

Griffith, who previously worked in winery office operations, now is pursuing a marketing degree at Sonoma State University. But on Halloween she expects to be home early giving 1,500 treats to costumed children.

"It's about six hours of handing out candy," she said.

Supplying the house decorations and costumes has become a big treat for the stores that specialize in Halloween.

"For us, this is our Christmas," said Cheli Martinez, manager at Partytime near downtown Santa Rosa.

She was quick to name the most popular item for home decor: "Every year it's spider webs." The store was sold out of that item last week but she hoped to get in more before this weekend, typically the kickoff for Halloween season parties.

Martinez worked off and on for 10 months this year preparing for Halloween. The costume dealers sent her online clips of the latest Iron Man and Superman movies in the hopes of boosting orders.

In Santa Rosa, Rich Geasland is gearing up for his first year hosting the "Crimson View Cemetery" at his home at the corner of Brandee and Crimson lanes. Even so, a friend's treasure trove of creepy paraphernalia has helped fill up his front yard.

The friend in past years hosted the Wicked West Ghost Town at a home in west Santa Rosa, an event that drew hordes of visitors and received favorable mentions from several who were asked about the county's top haunts. Now Geasland has set up some of its more memorable pieces, including life-size characters that shake wildly at the click of a remote control.

Geasland, a glazier, said he helped out at his friend's extravaganza and wanted to set up his own haunted spot partly because the experience takes him back to childhood.

"And I like scaring people," he added.

The spooky efforts can draw crowds. One haunter pleaded for anonymity, saying his Santa Rosa home — complete with guillotine — didn't need more visitors.

"I only have 900 candy bars," he wrote in an e-mail.

But others are welcoming crowds and planning to have their displays up and running well before Halloween. Gilroy intends to set out and retrieve her 15 animatronic characters each night starting Sunday.

She expressed confidence that her efforts would prove worthwhile, especially once she gets to see the faces of her younger visitors. But in a YouTube video posted last week, she did confide to feeling "a little bit of haunter's burnout."

"I know," said Gilroy, "that's what I get for starting in January this year."