Tilda Swinton's latest project gives new meaning to the term "sleeper hit." As part of a surprise performance art installation, the famously quirky Oscar winner, 52, has taken up residence at New York City's MoMA (Museum of Modern Art), where she is spending her days sleeping in a glass box.

PHOTOS: Redheads in Hollywood

"The Maybe," as it is called, will be taking place on random days throughout the rest of the month. Even museum staff doesn't know when the Moonrise Kingdom actress will show up, a source told Gothamist. When she does appear, she'll spend the whole day snoozing in her glass container, which is equipped with just a mattress, linens, and a jug of water.

PHOTOS: Tilda and other stars at London Fashion Week

Swinton, who hails from Scotland, conceived the installation nearly two decades ago and performed it for the first time in 1995 at London's Serpentine Gallery. She did a second showing in Rome a year later.

PHOTOS: Hot international stars

MoMA, for its part, has said very little about the piece, choosing instead to let the art speak for itself: "An integral part of The Maybe's incarnation at MoMA in 2013 is that there is no published schedule for its appearance, no artist's statement released, no museum statement beyond this brief context, no public profile or image issued," a brief explanation read. "Those who find it chance upon it for themselves, live and in real -- shared -- time: now we see it, now we don't."

This article originally appeared on Usmagazine.com: Tilda Swinton Sleeps in a Glass Box at New York City's Museum of Modern Art