Yep. All the time. People that can afford it pay a lot for panic rooms and hidden armories. Swinging bookcases, doors in wall paneling, you name it. People with that much money usually have something to protect.
Friend of the family works as a custom cabinetmaker. Most of his jobs involve him making secret compartments for rich clients. Mainly desks with a secret place that can hide guns, keys, ledgers and swords (oddly enough a lot of people request that),
I’ve been painting houses since I was 15. One was in a millionaire’s summer home. On the fourth floor of the house there was a closet on the same wall as the elevator. A section of drywall came away and lead to behind the elevator. There was a wooden ladder that went up and down the entire house; at the very top was a trap door that lead to a small room that was about 6 by 6 feet. It had windows and vents that could be opened or sealed completely. Pretty sure it was for their son to hotbox.
Never built one, but I did find one in a house I was doing some plumbing work in once. This was an expensive condo, and they had a secret office that had a secret one-way mirror looking into the GUEST SHOWER. Creepy as fuck, man.
Carpenter. I built a grow-room for a guy’s medical marijuana in Vermont. An alarm was wired directly to the state police barracks in the event of a burglary.
My dad is a doctor, and does a lot of construction at home on his free time. This one time he was moving a wall, making one room smaller and another bigger. He was putting an entire-wall-bookshelf kind of thing in the smaller room, and just to fuck with future homeowners he snatched one of those plastic skeletons from his job and hid it in the space between the bookshelf and the wall.
I expect headlines sometime in the future.
I built a Narnia closet for someone. Their daughter had one request for the new house: she had a built An armoire, white and modern looking with nice shelving units on the right side and a bigger opening on the left. However, when you pushed the back of the left, closet side, it opened up into an actual closet that was about 5×10 feet on the inside, not too shabby at all. Was a pretty fun build, albeit somewhat challenging.