Mistaken for Exhibit

My, what a stunning painting! The stark green lettering over a plain white background forcefully expresses the artist's quest for meaning and direction in a confusing world. Truly a masterpiece. What do you mean, it's the "Emergency Exit" sign? My bad.

Often intended as a Take That to contemporary art, this comedic situation involves somebody mistakenly believing that a non-artistic item among works of art is itself a work of art.

A variant involves non-artistic settings, such as an old person at an archeological exhibition being mistaken for a mummy. The inversion involves a genuine work of art being mistaken for a mundane item.

Compare Accidental Art. A person might invoke this trope deliberately to hide; see Nobody Here but Us Statues.

Examples of Mistaken for Exhibit include:

Advertising

In a Capital One commercial, the Viking mascots use reward miles to visit a museum. Naturally, they are mistaken for an exhibit.
One Subway commercial featured a man and a woman in a museum, marveling over the "simple yet majestic" art piece that consisted of a ladder leading up to a hatch in the ceiling, on which has been placed a Subway sandwich and accompanying drink. After much oohing-and-ahhing from the artsy-fartsy crowd, an air conditioning repairman climbs down the ladder, picks up the sandwich, and takes a huge bite from it. Then he climbs back up the ladder to the applause of the art fans, who are convinced it's a performance piece.

Literature

Several times in the stories by Ephraim Kishon.

Live Action TV

The Red Dwarf episode "Legion": Rimmer, pretending he knows about art to impress Legion, complements on one piece:

Rimmer: Now this three-dimensional sculpture in particular is quite exquisite. Its simplicity, its bold, stark lines ... pray, what do you call it?
Legion: The light switch.
Rimmer: The light switch?
Legion: Yes.
Rimmer: I couldn't buy it off you then?
Legion: Not really. I need it to turn the lights on and off.

The Doctor Who episode "City of Death": The Doctor and Romana leave the TARDIS at the Galerie Denise Rene. When they return, there are two people standing in front of it...

He: To me, one of the most curious things about this piece is its wonderful afunctionalism.
She: Yes, I see what you mean. Divorced from its function and seen purely as a piece of art, its structure of line and colour is curiously counterpointed by the redundant vestiges of its function.
He: And since it has no call to be here, the art lies in the fact that it is here.
(The Doctor, Romana, and Duggan run into the TARDIS, which dematerialises.)
She: Exquisite. Absolutely exquisite.

- And The Fires of Pompeii not only has the TARDIS mistaken for a modern art installation, but an enterprising street trader has sold it to a wealthy marble merchant, kicking off the Monster of the Week plot.
Murphy Brown: Eldin (Murphy's live-in housepainter) gets a show at an art gallery. At the opening people come in to find a completely empty room. They discuss whether they themselves are the art or what, but then Eldin points out that he painted a mural on the ceiling.
Parodied by The Chaser, who attempted to demonstrate that it was possible to dump all kinds of junk in an art gallery without people noticing: tree clippings ("Lord of the Plants"), an old computer, a broken vacuum cleaner (unsucessfully), an old mattress (unsuccessfully, though one woman spent some time admiring it) and two garbage bags ("Fun Dip").

Web Comics

Sandra and Woo got "New Exhibition Piece".

Sandra: Today I learned that modern art is indistinguishable from a janitor who’s fixing the air conditioner.
Larisa: Are you sure it wasn’t a piece of performance art?

Western Animation

The Simpsons: In the episode "Mom and Pop Art," Mr. Burns mistakes Homer's failed attempts at D.I.Y. crafting for fine art and buys them for large amounts of money.
In the Futurama episode "Mother's Day," the cast visits a wax museums of famous historical robots:

Fry: Hey, who's this guy?
Janitorbot: I'm the janitor. I'm trying to take a nap here.
Fry: I'm sorry, I-I thought you were made of wax.
Janitorbot: I am made of wax, what's it to you?
Fry: I mean I thought you were one of the wax robots.
Janitorbot: Is there some reason a robot made of wax can't take a nap standing up in the middle of a bunch of wax robots? Or does that confuse you?
[Fry backs away slowly.]

Real Life

An "illicit art mistaken for approved art" variant: Banksy has left his own reinterpretations of famous pieces in museums as though they were meant to be there. They often stay up for days or weeks before someone notices and takes them down.
Often inverted: You can put a "This is an art project" sign on almost anything, and people will assume it's true.
Workers Mistakenly Trash $50,000 Artwork.