Before Colette left Vermont in fall 2023 for her winter home in Bonita Springs, Fla., a neighbor offered to keep an eye on her house while she was away for six months. Though it was a generous offer, the retired widow from Williston didn't feel comfortable imposing so much responsibility on a neighbor, especially one who refused to accept payment for his time and effort. Then Colette heard about Vermont Home Watch. The Jericho-based business promises to keep houses safe and secure while their owners are out of town for a week, a month or a year. "I thought, This is perfect, because I'm always looking for somebody to take care of my property while I'm gone," Colette said. (Like all the homeowners interviewed for this story, Colette asked that her last name not be published because her house is unoccupied for much of the year.) Vermont consistently ranks in the top three states for second-home ownership, with about 17 percent of all residential properties listed as recreational or seasonal, according to the 2023 U.S. Census. With many of those houses and condos sitting vacant for months at a time, a cottage industry has sprung up to keep an eye on part-time residences while their owners aren't there. "A lot can happen to a home when it's unoccupied," said Charlie Posnick, co-owner with his wife, Kim, of Vermont Home Watch, which serves all of Chittenden County as well as Waterbury, South Hero and Grand Isle. Posnick, 65, launched Vermont Home Watch in December 2022 after retiring from a career as a software tester at Dealer.com. Eager to remain busy into his retirement, he heard about the National Home Watch Association, an industry trade group that trains and certifies home-watch professionals. Posnick's is one of three such businesses in Vermont and the only one that is nationally certified. Elsewhere, home-watch professionals have operated for more than 20 years in such places as Arizona and Florida, where seasonal properties are common. The national certification requires home watchers to be insured and bonded and to undergo training and criminal background checks. Posnick's clients are mostly snowbirds and professionals who travel frequently. Occasionally, he's hired to watch vacant houses that are part of decedents' estates that are going through probate court and cannot be sold yet. One of his clients is a family relocating from Georgia, who engaged him to regularly check on…