They are faked, at least partially.

I was friends with a guy who was on an episode of a one season HGTV show called "Container Homes." He and his wife at the time actually wanted to buy or build a container home.

They had talked to a developer and were going to have one built. Got on the show somehow. After the show started filming, some off-screen drama happened with the developer, and an HOA or zoning board or something, and long story short they were denied the permits to build one. But the show wanted to keep going, so they used the construction of developer's office, which was also a container building, for footage, and when it was completed did a super quick, rather pathetic job of making it look like it was decorated as a house. Then filmed the "reveal," which at that point was just kind of rubbing salt in the wound. He looked so dead inside, it's hilarious.

A lot of the house hunter-type shows are allegedly shot with couples who are already closing on a house, and then HGTV just takes them out and films them just looking at other houses literally for show.

I always figured they paid people to act excited on The Price is Right.

Imagine if someone didn’t even want to be there and just went to the studio because their family surprised them with tickets while they were on vacation. Then they get picked and super grudgingly go through the whole game.