Monster mask, circa 1940, of waxed buckram with hemp hair.

Hep Cats, early 1950s. Rayon jumpsuits with plastic masks manufactured by Ben Cooper.

– It was a dark and stormy night — but Phyllis Galembo had a lot of company. Her costume collection now numbers around 500 spooky and suspiciously friendly characters as well as assorted heads, hands and feet. A photographer and professor of art at SUNY-Albany, Galembo started out searching for interesting images and — in a familiar process many will recognize — ended up a serious collector with a studio full of stuff.

An exhibition featuring her collection, “Dressed to Thrill: Halloween and Masquerade Costumes with Photographs by Phyllis Galembo,” is on display in The Museum at the Fashion Institute of Technology through January 4, and will travel next year to the Albany Institute of History and Art. The show displays dress-up attire spanning the century 1870-1970.

A special plus is the accompanying volume, Dressed to Thrill: 100 Years of Halloween Costumes & Masquerade by Galembo published this year by Henry N. Abrams, which includes guest essays, such as Mark Alice Durant’s informative and entertaining “Glowing Turnips, Pointy Black Hats & Insomniac Aliens: The Hybrid History of Halloween.”

Valerie Steel, chief curator and acting director of FIT’s museum, wrote the book’s introduction and likes to quote novelist Henry Fielding when he said that “to masque the face” is “t’unmasque the mind.” She says, “In every age, you could express your inner fantasies and dreams through your costume.” One of her favorites in Galembo’s collection is “Evil Bunny,” a 1930s face mask of waxed and painted buckram. “It’s a bunny mask but it’s a demented bunny mask.”

Galembo’s previous books, such as Vodou: Visions and Voices of Haiti, indicate a longstanding interest in ritual, and since the 1970s she had been photographing subjects in festival and theatrical costumes. But her focus on the American Halloween holiday began simply: she wanted to capture images of her niece and nephew in interesting costumes.

In Dressed to Thrill, Galembo writes: “I had hoped to photograph them both in Halloween costumes I found in flea markets, on the Internet, and in the outdoor market areas in my Chelsea neighborhood in New York City. Once started, I began collecting in earnest to visually illustrate my interest in how people use these costumes to assume different identities…. It was not my original intent to create a collection that would overflow my apartment, but it did!”

She recently underlined her amazement: “I really did it just to have props to photograph. I didn’t set out to be a collector. I became a collector and I have a huge collection — it wasn’t planned. I was interested in older costumes, particularly ones that were homemade or handmade. Even a lot of early mass-produced costumes were basically made by hand.”

She continues, “I live near the 26th Street flea market in New York City, and I’ve been collecting for 17 years, so some of the earliest ones came from asking dealers to look for me. I don’t necessarily care when they were made, but some of the more interesting ones happen to be the earlier ones.” She cites, for example, a homemade multicolored jester mask with attached bells, circa 1910-1920, that she found in New Hampshire. Another interesting find in New York City was “Devil Boy,” a homemade red cotton jumpsuit dating to the 1890s, decorated with a hand-embroidered pitchfork and accompanied by a cape and hood with horns.

Inextricably intertwined with religious and theatrical ritual, the history of masks and character costumes is too vast to outline, except to say that human beings seem to have a universal desire to dress up as something else. The roles people now assume online in adventure games and chat rooms is just a modern manifestation of the need to disguise the truth. Recent costume history might begin, however, with Carnival celebrations before Lent and the court masques, or costume balls, of the Seventeenth and Eighteenth Century.

If the history of costume is complex, the history of Halloween is even more so, combining threads from Roman, Celtic and Christian traditions mixed in with practices like begging for pennies on Guy Fawkes Day in England. Immigrants to North America brought along their own local practices for All Soul’s Day or the Day of the Dead at the end of October. Like Christmas, Halloween was domesticated by the Victorians — with their helpful craft suggestions — and turned into a popular secular celebration. Planned parties, parades and pageants help tame the wild, pagan past of this popular holiday.

The Twentieth Century brought a proliferation of costume patterns in periodicals that mothers could sew at home and, eventually, advertisements for commercial costumes. Earlier examples of the latter were made of cotton with masks of stiffened buckram or gauze. By the 1950s, companies such as Halco and Collegeville were stamping out plastic masks to accompany costumes of synthetic fabrics. One interesting aspect of Halloween that still retains its popularity is the use of masks and accessories — ears, beards, tiaras, swords, pitchforks, etc — with an improvised costume to create an instant princess or pirate.

Anyone who has gone trick or treating knows that a scary costume looks even more frightening under the right conditions — just stand in the dark with a flashlight under your chin. Galembo is above all an innovative photographer, so the exhibition is not only about her collection but about how she “sees” the costumes in her photos. Some are worn by children surrounded by props, others are just mounted on a background, but the magic comes from the way in which the artist illuminates and exposes the images.

As with “Evil Bunny,” sometimes the most chilling images are supposedly friendly characters. A 1950s commercial Humpty Dumpty with an egg jumpsuit that snaps up the back is smiling far too much for comfort. A large plastic clown head with rayon costume manufactured circa 1959 by Halco makes the viewer want to run in the opposite direction. And Galembo’s photograph of a 1930s Donald Duck suit with buckram mask by A.S. Fishbach, Inc, of New York City makes the cartoon character look like some primitive tribal bird totem.

Many costumes are very era-specific, designed to appeal to children attached to the pop culture of that day. A Charlie McCarthy outfit, circa 1938, is photographed in the suitcase where the famous ventriloquist dummy lived after hours, and a 1936 red dress says, “Leapin’ Lizards! It’s Little Orphan Annie.”

Any boomer glued to early 1950s television could identify the Howdy Doody mask or a complete Clarabelle the Clown costume made by the Bland Charnas Co. and found in Wisconsin. Also hot in that decade were robots and other figures from the galaxy, such as the circa 1959 “Space Bug” with plastic mask and rayon jumpsuit by Halco.

The Museum at the Fashion Institute of Technology is located on the southwest corner of Seventh Avenue at 27th Street and is open Tuesday-Friday, noon to 8 pm, Saturday 10 am to 5 pm; admission is free. For more information, call 212-217-5800 or visit the website .