Nor, for that matter, do they even have mains electricity. Stiltsville is just what it sounds like - a cluster of homes on stilts in the Bay of Biscayne, almost 10 miles out from Miami.
It is an eccentric anachronism without a church or post office, yet there have been homes here since the late 1930s, at one time as many as 25, all simple wood structures perched on concrete pilings. In the immediate post-war years, Stiltsville gained a reputation as a place of mild sin with the Bikini Club, a converted 150ft yacht, which played host to illicit gambling and naked sunbathing on deck.
Those days have gone. Federal agents shut the Bikini down in 1965. That same year Hurricane Betsy destroyed most of the homes. But against all odds, this speck on the maritime map of Florida survived. There are seven structures now - some weekend retreats, others homes for boating and fishing clubs.
But Stiltsville was never meant to exist, and soon it may not. In 1980, the Bay of Biscayne, a huge expanse of turtle grass under just a few feet of warm, Gulf Stream waters, was designated a national park by Washington. The homes were protected by 25-year leases granted to the owners by the state of Florida. Those leases, however, expired in July and the park authorities were always clear that they would not be renewed. Instead, the owners were under orders to dismantle the structures and to leave.
The community, however, is putting up a fight. With the help of a Republican congresswoman from Miami, Iliena Ros-Lehtinen, a reprieve has been negotiated until 1 December 2000. Unless a truce can be negotiated before then, however, the order to vacate will remain in place.
Gail Baldwin, a Miami architect, could hardly find words to express his disgust. "This is a unique part of Miami. It's as if they are handing us the bullet and inviting us to shoot ourselves," he lamented. From one side of Mr Baldwin's home the view extends to the horizon of the Atlantic. Look west and all of Miami, with its glass towers, seems to float on the ocean.
For the National Parks Service, however, this is meant to be pristine territory and allowing private dwellings to remain on it was never an option. Indeed, expunging private owners is Parks Service policy all over the US. "When the park was created, there was nothing in the legislation about preserving Stiltsville," Rob Shanks, a park ranger, explained.
Just how Stiltsville is damaging the park is less clear. Mr Shanks made a stab at explaining: the turtle grass can't grow under the houses; there could be chemical leaks from their sewage tanks. He does not address what kind of damage might be caused by demolishing the homes and lifting out the concrete pilings, however.
Mr Baldwin and his friends, who are co-ordinating a "Save Old Stiltsville" campaign, now have a year to change minds in the Parks Service. They have gathered 50,000 signatures for a petition. And Ms Ros-Lehtinen has promised to introduce a bill in Congress that would carve out the plots where the homes sit from the park itself. But the authorities are resisting.
Putting up the lights today is not really about Christmas. It is Stiltsville's message to the Parks Service: "We are still here." Will they be doing it again in a year from now? Probably not.