Nights, weekends, vacations, every spare moment of their lives is devoted to their "habit." Folk art collectors are a peculiar breed - unabashedly acquisitive, they delight in the art they collect and the vicarious involvement it gives them in someone else's culture.

The obvious result of such unbridled passion is a set of people whose entire living environment is cluttered with collections of things - everything from hand-painted carved duck decoys to a wall filled with Mexican masks.

For lawyer Pete Cecere and teacher Mimi Wolford, individual passions have forced them into side businesses selling objects and artifacts to support their habits. For lawyers Jan and Charles Rosenak, it means every business trip is preceded by dozens of phone calls and elaborate arrangements to make contact with contemporary folk artists living in hard-to-reach places. For lawyer William Butler, it means an annual pilgrimage to the big decoy auction held every summer in Hyannis, Mass., and lots of long distance phone calls to other collectors interested in buying and trading decoys.

While their specific passions vary, all share a love of being surrounded by interesting, unusual objects. The most extreme example of a collector gone wild is Pete Cecere, who lives alone in a five-bedroom Reston home crammed with objects and artifacts from Mexico, Chile, Uruguay and the United States.

"My house is my dependent," says Cecere. "I know when I came back from South American (where he worked with the International Communications Agency) that I had to have a place to hold all this stuff - it had been in my head for years."

Walking into the bearded collector's home is an experience. The 14-foot-high living room wall is covered with handmade Mexican masks. An 8 1/2-foot-tall papier-mache skeleton he calls "Getrude and the Nightwatchman" made for an All Souls' Day celebration, stands casually in one corner. The basement, paneled in barn siding, is what Cecere refers to as a "stylized reproduction of a 19th-century general store," complete with wooden boxes filled with fake wooden fruit made in Mexico. There are rooms housing everything from American carrousel figures to pre-Columbian art. "If I see something I like," said Cecere, "I buy it." His feeling is echoed by many other collectors, all of whom remember sadly "the one that got away."

Are such compulsive buying habits just this side of crazy? What kind of people are so involved in material things?

"My ex-wife would tell you that I have an anal retentive personality," said Cecere, who sold his antique American gun collection several years back to pay for his divorce. But Cecere and other collectors of folk art are comfortable with their passion for things.

"I believe it is extremely spiritual to be surrounded by beauty," he said. "You have to share that beauty with your friends - share that enthusiasm. My home is a very personal statement. You don't have to like everything I like, but at least you react. I can't stand it when someone walks into my home and doesn't say a word."

It's hard to react to the environments created by these collectors. The furniture, even the architecture of their homes, becomes merely backdrop for their collections. An exception is the District home of William Butler. The first floor holds a smattering of decoys, tastefully placed on pieces of antique furniture. It is only when you enter his den that you see a wall filled with ducks that you get the full thrust of his enthusiasm for his collection.

It is a willingness to share their private loves that seems to characterize all collectors. Lillian Saxe, a retired social worker, has so many collections of things which delight her that she rotates them and stores the rest in old Xerox paper boxes.

"You must come see my collections," said Saxe enthusiastically, ticking off a variety of objects ranging from handmade decorative eggs to miniature fish. "And," she added with tongue in cheek, "you can even see my collection of empty Xerox boxes."

That reminded her of the story of the lady who went to visit a psychiatrist. When he asked her why she came, she said her family thought she ought to see him because she liked pancakes so much. "There's nothing wrong with liking pancakes," replied the psychiatrist, "I like them myself."

"You do," exclaimed the lady, "then you must come to my house and see my three trunks full!"

Folk art collectors can scarcely be put in the same category - except when it comes to enthusiams for the objects they collect. None of the people interviewed is fabulously wealthy. Their jobs are not directly connected with their passion. They are not collectors on the scale of Abby Aldrich Rockefeller, founder of one of the country's leading folk art collections, or Jean Lipman or Herbert Hemphill, two other major collectors. In fact, it is only in recent years that folk art has been accorded the same prestige or generated the same kind of popular interest as so called "fine art." With some notable exceptions, folk art has been buried in the halls of natural history museums, viewed as quaint reflections of cultures not to be confused with "art" by recognized masters from recognized schools of artistic thought.

What then is folk art and why is it so intriguing to this new set of amateur collectors?

There is still no single definition. Some say it is a naive, largely untutored expression of a culture. Others say that if it is to be called art, it must have been created without any utilitarian function in mind, that it must spring from the mind and heart of a individual who sees his or her world through different eyes.

Elaine Eff, curator of a forthcoming exhibition of folk art and folk life scheduled for the Renwick Gallery, says that "Folk art is any handmade object embellished beyond necessity." Blurring any distinction between objects of pure fancy and those designed for their utility, she points to the importance of the individual artist's inspiration and the cultural traditions from which the work springs. For folklorists, folk art is more important as a reflection of a flow of traditions rather than for its unique qualities.

For the collector, it is only the delight in owning the object - whether utilitarian or pure fantasy.

The enthusiasm for the object and the interest in the culture from which it stems are not the only things these collectors have in common. All are inveterate savers and can trace long histories of collecting habits. William Butler used to collect English pewter and 18th-century English antiques as well as 19th-century American impressionist paintings.He recalls collecting both coins and stamps as a child. As you walk out of his antique-filled home, he points to a modest collection of antique canes that is a side hobby of his. Charles Rosenak has a basement full of dinner plates with politicians' faces and slogans on them that dates back 25 years. Jan Rosenak's antique postcared collection, started as a child, is now housed in the Smithsonian. Mimi Wolford, who collects Haitian and African Art, unusual jewelry and clothing, still has small silver box she bought in Indonesia at the age of 8.

Memories of "the hunt for a particular object are part of the joy collectors share. Folk art collectors have marvelous stories to tell about the manner in which they obtained their adult toys. Mimi Wolford tells the story of visitng a Moslem Salah celebration in Nigeria several years ago to help buy things for Ohio University's collection of African art. She was thrilled with the whole celebration but felt it gauche to start bargaining for goodies while the festivities were on.

"After the celebration was over," recalled Wolford, "I was walking down the street, and a horseman rode by with the most wonderful talking drum that you beat and squeeze. I asked him in sort of sign language if he would sell it to me. We agreed on a price and I paid him for it. I had it in my hands and I decided that I just had to have one for myself as well." At this point, Wolford's face broke into a great smile, remembering the acquisition of this precious drum. "I asked him, again in sign language, if he knew where I could find another like it. He took back the drum and I thought, Oh dear, he doesn't understand, he thinks I don't want it. He beat out a message on the drum and suddenly from around the corner rode another tribesman with a drum just like it and I bought it too?"

Few of these seemingly impulsive people operate on instinct alone. Most are students of the cultures they collect from as well as students of the market. "A few years ago I could pick up a good quality decoy for anywhere from $10 to $250," Butler recalled wistfully. "Now it's gotten too precious - why a twin to one of the ducks in my collection just sold for $7,500 - that's crazy." Yet Butler Follows the craziness by taking the important journals in the field for collectors, including one that lists prices for decoys by certain famous makers. Mimi Wolford, having lived abroad for most of her life, has a good idea of the market value of objects in the countries where she buys. But concerned for the artists' well-being, she takes care not to pay too little for her purchases.

The Rosenaks began their contemporary folk art collection five years ago after being squeezed out of the market for contemporary abstract and kinetic art. They became enthralled first with New Mexican folk art and their tastes and collection grew from there. They began by reading authoritative books on contemporary American folk art, visiting galleries and auctions. Now they read journals most people have never heard of and try to find a path to the doors of the folk artists before galleries get there and tack on 50 percent commissions.

"You see," observed Rosenak, "galleries can control the serious non-folk artists, but the folk artists are in a different league. They don't exist to be 'shown' by any gallery. They produce for their own personal enjoyment." As a result, the Rosenaks have some good 'buys' in contemporary folk art, having paid less then $500 a piece for most works, as little as $10 for some.

"The hunt," Cecere said, "is part of the fun of it. You compare prices sometimes, but really it's a matter of how much you're willing to pay to have something become part of your environment, part of your life." CAPTION: Pictures 1, 2, and 3, Mexican masks line an entire wall in Pete Cecere's cathedral ceiling living room (above). The skeleton in the corner is one of many he has collected at Mexican All Souls' Day observances. His Reston "playroom" (below left) is filled with his favorite 19th-century toys - a complete stylized reproduction of a general store. Mimi Wolford (below right) sits surrounded by Haitian and African art, dressed favorite piece of folk art clothing.; Photographed by Bill Snead