Enter at your own risk!

Inside the garage, in a cobwebbed maze occupying 600 square feet of styrofoam walls, movable doors, and strobe-lit passageways that took six weeks to assemble fully, half a dozen costumed spooks are scaring the living daylights out of anyone brave enough to enter the family’s elaborately decorated haunted house.

Flapping bats, creepy-crawly spiders, and amputated body parts are all on display. But this is a homegrown spookfest taken to a whole other level, way beyond ghostly lawn decorations and fog machines. In one “room’’ of the twisting labyrinth, a mother sits rocking her ghoulishy deformed baby. Mind fetching her a fresh bottle from the fridge?, she asks. Those who comply are in for quite a shock.

Farther along, Convict No. 666 (played by neighbor Greg Keefe) is getting the jolt of his life in the Torture Chamber’s electric chair. That caged werewolf snarling in the corner? Not so caged, it turns out. (Underneath the fangs and fur: 9-year-old Lindsay Marchese.) On and on the horrifying happenings unfold. When it comes to scaring the boo! out of trick-or-treaters, the Marchese house is a masterpiece of homegrown ingenuity - and a fright to behold for kids and adults alike.

“It freaked my guts out!,’’ exclaimed 10-year-old Tom Hunter of Weymouth, emerging from the rear exit during a Halloween party at the Marcheses’ last weekend. Kathy Marchese, dressed in a Morticia-esque witch’s gown, stood at the entryway, dispatching groups of two or three at a time inside the maze. Even though they tone down the scare tactics for smaller children, she said, any child 5 or younger is advised to keep out. “We keep adding new elements every year to make it even scarier,’’ she added with obvious relish.

The Marcheses’ come-inside-if-you-dare display - Kathy is a Halloween fanatic; her husband, Mike, an electrician, is handy enough to build and wire almost anything - is a baroque example of what Halloween expert Lesley Bannatyne calls “upping the ante’’ on Halloween decor. According to Bannatyne, the author of four books on Halloween trends and rituals, the growth in elaborate home and yard displays has escalated noticeably in recent years, fueled by Halloween-themed websites and chat rooms, where enthusiasts trade tips on everything from sound and lighting effects to costuming and makeup, and by a burgeoning home-decor industry catering to every nightmarish desire imaginable.

“Halloween has a darkness and quirkiness to it that seems to liberate peoples’ imaginations in ways other holidays do not,’’ Bannatyne says. These impulses seem to grow over time, not diminish, she says. Teens too old for trick-or-treating trick out their basements with over-the-top Halloween decorations. Later, they acquire “the means, methods, and motives’’ to work on a grander, more theatrical scale. “We’re becoming more theatrical, anyway,’’ she notes. “On Halloween, it all seems accessible. You can do theater in your own yard. What you’re seeing these days simply reflects what’s going on in our culture, and we are a gory culture.’’

Also a free-spending one. The National Retailers Association estimates Halloween spending this year will average around $65 per person, up $6 from a year ago despite a shaky economy.

Tonight in Marblehead, Roy and Heather Martin’s gothic Victorian house will be transformed into Birthday Party Gone Bad, the theme of this year’s annual horror show staged inside the Martin manse. For Heather Martin, it’s not about buying the latest animatronic goblin or glow-in-the-dark vampire - virtually all her costumes and props come from flea markets and swap meets - but about fully embracing the Halloween spirit, which means putting on a show so hair-raising that trick-or-treaters have been known to line up for 30 minutes or more to experience it. The couple has been steadily expanding their spookhouse over the past 10 years, adding elements that “push the envelope’’ on the macabre, as Martin puts it.

“The house looked awful - and scary - when we first moved in,’’ she recalls. The Martins decided to dress it up for Halloween, a holiday she always loved as a kid, first coming up with characters for each of them to play - he’s the Dead Butler outfitted in a tuxedo, she’s some variation of Crazy Woman in Evening Wear - and later recruiting friends and relatives to flesh out a cast that has grown each year as well. Tonight’s festivities will feature nearly 20 players, ages 8 to 70.

The birthday party “starts going bad,’’ says Martin, when guests move past the friendly Birthday Clown at the front doorway and enter the living room, where a child strapped inside a straitjacket hints at darker things to come. Moving on to the adjoining dining room, they’ll find the usual array of foul food - one year it was live mealworms - before reaching the kitchen, where the Birthday Girl will be having her leg sawed off by a demented butcher. By then, Martin figures, the terror index should be peaking. More props and spooky effects in the backyard and driveway should finish the job “I think less is more, though,’’ says Martin. “What really creeps people out is behavior that’s a little off, a mix of what’s real and unreal.’’

Maureen Watson has been spooking out her two-car garage in Braintree for the past five years. With the help of her son, Kevin, and his friend Jordan Tuffo, she’ll be putting on a show tonight for scores of trick-or-treaters roaming her neighborhood. Inside the garage, strobe lights illuminate a beheaded bride, spiders dangle from the ceiling, and a remote-controlled Mini-Me monster patrols the premises menacingly. Like the Marcheses, Watson warns the very young to stay outside. “We’ve kept adding and adding every year,’’ she says. “Most kids end up running out the door.’’

Joseph P. Kahn can be reached at jkahn@globe.com.