NEPO spells "open" backward. NEPO House is a place that is not quite a backward open house, but an open house turned inside out: The house is not the focus. The house, on Beacon Hill, where artist Klara Glosova and her family live, is colonized by ever-changing art. A wine bottle may be spilling wine continuously in the recycling box under the kitchen counter—it's actually a fountain sculpture by Glenn Herlihy. (You can drink from it.) Or, on the floor next to the bathtub upstairs, there may be a pile of gray marble shavings representing the leftovers from the work Dan Webb made for a highfalutin commercial gallery show—possibly Webb's little homage to the piles of earth taken from remote places and displayed in New York galleries in the 1970s by Robert Smithson. A performance artist may be in the shower.

Every part of NEPO House—the pillows on the master bed, closets, the front of the refrigerator, countertops in the kitchen—is treated as a canvas. The House is open for one night every few months with a different theme, and this Saturday will mark the fourth time. This month's theme is "Back to School, Back to Earth Special!" The long list of participating artists would probably be full of familiar names if they all weren't using pseudonyms: "Mrs. Evelyn ShaBOOBY," "Randy Dodge," "Buckminster Fullest," "iateit yesterday." Some barely conceal: I do not know Mrs. ShaBOOBY or Mr. Fullest, but "Claude Bourbon" is Claude Zervas, I presume.

NEPO 4, Glosova's website says, "is about learning." "Inspired by the plight of guinea pigs," the artists subjected themselves to all sorts of experiments, and the results will be displayed in the style of a natural history museum. "Exhibits will contain live humans (performances), objects, and missing objects (some exhibits may be temporarily shut down due to a lack of funding)." Identities will be revealed.

The theme of NEPO 2, which I attended in March, was twinning, which included a white puddle sitting on the floor, looking very lonely, until you looked up and saw it on the ceiling, "reflected" in wood; a painted ceramic mountainside on the foyer floor, lifted straight from a thrift-store painting in the living room; clip-on earrings made of human hair in a box on a bedroom dresser.

Nothing was labeled, so it was sometimes hard to tell what was art and what wasn't. Jason Hirata's backward drawing of an IKEA sink-installation manual on the refrigerator? Art. The climbing wall in the child's bedroom? Not art, just really fun. You could live like this, or more like this. recommended