I've sat on this news story for a few days because I couldn't find it in what I would call a quality news source to support it. But NPR reaches that bar, so it's probably true that Italian artist Salvatore Garau sold an invisible, intangible sculpture.
High Snobriety has details about this artistic wonder:
Garau instructs that the sculpture will need to be displayed in an unobstructed area that is five feet by five feet. It should also be displayed in a private home. And it may be displayed in any light since it's not there.
Embedded above is an Instagram video of a previous work by Garau, which is likewise more conceptual than existential:
Last month, Garau displayed another immaterial sculpture titled, "Buddha in Contemplation," in the Piazza della Scala in Milan, near the entrance to the Gallerie d'Italia. Garau posted a video of the "statue" to his Instagram page, writing, "Now it exists and will remain in this space forever," says the video. "You do not see it but it exists. It is made of air and spirit."