Word or phrase for fake appearance or posturing

I'm looking for a noun (it has to be an object) that expresses the concept of fake appearances.

In Spanish, we can express that with the word "facade" understood as the front of a wall (but part of a building) because a beautiful facade can hide horrible things inside of the building (things that we don't discover until we enter). The cover (of a book) can express that concept as well.

To be more specific, I'll give you some examples in Spanish:

• Era todo fachada. (It was all facade).
• Cuidado con las fachadas bonitas. (Beware of beautiful facades).

The concept that I'm looking for is usually used to express deception after realize that you were wrong about someone. I'd like to emphasize that I'm not looking for an adjective or abstract word (or expression) but for a physical object.

Is there any word in English to express that?

Solution 1:

Façade is used also in English:

[ S ] a false appearance that makes someone or something seem more pleasant or better than they really are:

• He kept his hostility hidden behind a friendly façade. We are fed up with this façade of democracy.

(Cambridge Dictionary)

The term facade has been used figuratively from the first half of the 19th century:

1650s, "front of a building," from French façade (16c.), from Italian facciata "the front of a building," from faccia "face," from Vulgar Latin *facia (see face (n.)). Figurative use by 1845.

(Etymonline)

You also have a few sayings such as:

appearances can be deceiving and don't judge a book by its cover