HE WAS 75 and in ruddy, robust retirement. He was one of the millions of snowbirds from the Frost Belt who made the yearly migration down I-95, the concrete spine of Florida, for a couple of weeks of golf and goofing off. After so many trips back and forth from Morris County, N.J., he decided to build a permanent nest in the central part of the state. There he would fulfill his dream of owning a little bungalow only a chip shot away from a palm-fringed country club.

The retirement community he and his wife decided on was a sprawling tract of neat-as- a-pin duplex homes in the Kings Point subdivision of Sun City Center, a little south of Tampa, straddling the Tamiami Trail on the west and the meandering U.S. 301 on the east.

The fine, predictable weather and the golf were two compelling reasons for selecting Sun City. But there was another: You had privacy and security. The community has a gate house and uniformed guards. You have to be at least 55 to get in. Children and pets are forbidden, except as guests.

The real estate lady introduced them to residents who enthused about not having to lock their house or car doors at night. These were people from Pittsburgh and Hartford and Boston. Sure, the weather was the big attraction, but not having to deadbolt your front door!

His wife was not a great golfing fan, so for her the idea of living on a fairway elicited nothing but concern that someone might slice a five-iron shot through the living room window or crunch over the shrubs with his electric cart. But she found his enthusiasm contagious when he saw one of the attached bungalows for sale about 50 feet away from the apron of the 15th green.

The house cost $58,000, which they had in cash, having gotten equity from the New Jersey house and redeeming a couple of the CDs.

Just as they were preparing to move into their button-bright bungalow, after she had made all the decorating plans and had ordered Florida-style furniture from a store in Bradenton, he was run down and killed by a 16-year-old who told the police his attention had been distracted.

There she was, with a house on the apron of the 15th green, alone but for some new neighbors who helped her make the funeral arrangements. The funeral home director, graying and Izod-shirted, recommended a nondenominational minister for the nonpracticing Presbyterian deceased.

"He lived for the game of golf," said the minister, concluding the service. "And, like all of us will one day, he's made it to the 19th hole."

The funeral home provided piped-in organ music. Subliminal Muzak. "Blue Moon" and "Theme from a Summer Place." Fellow Northern New Jerseyites, bronzed-faced and lacquer-coiffed, stood in an awkward receiving line to console; men in blazers and flannel trousers, women in lime-and-white flowered pantsuits.

The widow's immediate needs were basic transportation. Her social security benefits would keep her comfortably above the poverty line, with the house free and clear and with no need to spend those New Jersey dollars for heating oil and winter clothing. Church, bank and community center were a painful walk for a 76-year-old. A car made no sense, nor did a bicycle. The smart alternative for her, and hundreds like her, was a golf cart. They are cheap to run, simple to operate, silent and as individually tailored to the owner's sense of status as anything custom- ordered from Detroit.

Golf carts are ubiquitous in Sun City. They are driven by people like George, who's legally blind, hard of hearing, but as mentally sharp as he was when teaching school in Indiana 20 years aog. George had been involved in only one serious accident. He had bounced over a speed bump at 20, lost control and struck a tree. He had seen neither the bump nor the tree. The mishap did nothing to cool his passion for tooling around Kings Point in his repaired cart. He allowed it was the best fun he had had in years.

A neighbor helped the widow select a cart that would meet her needs. Four wheels (the tricycle type, while cheaper, can tip), a plastic enclosure (for those occasional windy, rainy days) and carpeted floor. A local dealer had a couple of models on display in his showroom. Each cost $3,400 (AM/FM/cassette player would be $300 more). The widow selected a Club Car, without radio, which probably ranks between a Pontiac and an Oldsmobile on the GM status scale. At no extra charge, the dealer agreed to paint on a racing stripe. Like George had on his.

From the widow's subdivision, she could cart along State Road 674, cross at the signal and attend church or pick up a bag of groceries at the Winn-Dixie. That route causes her to pass a Y-shaped high-rise known as the Trinity Lakes facility. It is pleasantly landscaped, with big, cheerful windows. It is a home for the aged and enfeebled, providing full-care medical service. It is where Sun City residents go when they no longer can maintain their little bungalows or navigate their golf carts.

The Trinity Lakes Full Care Facility towers over the shopping complex across the state road. One of the buildings houses a movie theater that plays only Spanish language films. Migrant workers are the patrons. Sun Cityites see "My Fair Lady" and "The Sound of Music" for a dollar in their clubhouse.

The Sun City developers began with the notion of a community theme. Olde English, judging from the street names: Gloucester, Canterbury, Bedford, Dorchester. The theme extends to the Inn, where the Elizabethan concept seems to have collided with the International House of Pancakes. The Inn's facade is Tudor. The tables are formica, and Priscilla plays the organ, weekends, for your dining and dancing pleasure. "Besame Mucho" and "Around the World in Eighty Days." Some couples dance. Others sit and talk golf or bridge. The mood is one of the subdued, candlelit cheer.

Back across the state road, at the Georgian-styled clubhouse, square dance instruction is available, along with rooms for crafts, conferences and exercising. The clubhouse features both indoor and outdoor pools. A sign at poolside contains 12 printed regulations. One is "No Horseplay." Another admonishes against climbing on or jumping off the furniture.

There is a determined effort by the Sun City management to keep things moving, to make things right for cheerful mixing. Dances, bingo, nature walks, bike trips, cheap bus service to Tampa and Bradenton.

The widow, an intensely private person, preferred the solitude of her living room facing the 15th green and the afternoon companionship of "Search for Tomorrow." She would use the Club Car once weekly, fearing to drain the battery and unsure of the procedures for charging it again. She would use it to take her along State Road 674, which she would cross at the signal to park in the "carts only" section of the church lot. Her weekly excursion from Canterbury Lane would take her directly past the front lawn of the Trinity Lakes Full Care Facility, where Sun City maintenance men would be sprinkling and fertilizing, hoping to coax verdant life from the sun-bleached, tired grass.