In movies, how come ghosts cannot touch physical objects and can pass though door/wall but at the same time able to sit on couch just fine?

Basically you’re just not supposed to notice that.

While you’re at it, you might also ask why they’re wearing clothes.

It’s a movie—you’re not supposed to think logical.
The movie Ghost with Patrick Swayze addressed part of that. He couldn’t pick up items but learned how to move items.
They have to wear clothes to keep the movie from being rated R or XXX
This little girl sees her deceased mother and interacts with her. Now any movie depicting ghosts this way would be boring

Right? The floor too, and they still seem to be mostly restricted by the force of gravity but don’t plummet towards the core.

Short answer, it’s useful for telling stories. Ghosts aren’t real so there are no rules.

The ghost would only appear to be sitting on the couch. If you could look more closely you would see that the ghost is just a thin grey or brown mist and the couch seat beneath it is not depressed. Ghosts cannot touch objects and you cannot touch a ghost. You would just feel an unpleasant chill if you tried. Ghosts have been known to throw things and at least one can play the piano but I don’t know how this is possible. Next time I see one I will ask, or perhaps not.

They will it to be that way.

Because it’s all make believe.

You could think of it as them just having it in their memories that they used to sit on chairs/couches, so they are going through the motions.
They are not actually sitting on the chair, but are floating just above it, in a memorised pose.

Loli beat me to it. I think it’s the memory of sitting on a couch.

@Smashley I didn’t even think of that.. But yeah.

Thanks for the answers.. I guess it’s a movie thing and I’m not supposed to notice that and think logical. It’s understandable about the cloths, since they died with cloths on so the ghost is wearing the same cloths.

Well, the understanding of ghosts is that they are bound to moments in time, regardless if time has changed the environment. For example, a ghost that passes through walls… how do you know that wall was always there? Houses and buildings get remodeled a lot, especially the older haunted ones. Ghost follow the paths they walked while they were still alive, which includes going through doorways or up stairs that have been moved and are no longer there.
A ghost is not a tangible being, they cannot interact with the physical world, and thus are not affected by gravity or physics.
But ghosts are memories of the living. So they remember sitting on couches, and thus continue to do so. You don’t pass through a couch, you sit on it.
But if a wall is present that was not there when they were alive, they will not recognize it as a wall at all- they still see it as an open walk-way.
You will notice that ghosts only tend to interact with antique furniture- things that would have existed/been present when the ghost was still alive. Because ghosts do not adapt, they do not change, grow, evolve, or learn. They are memories of the living. Like a photograph. A ghost girl could move the antique doll that once belonged to her, but she can’t pick up an iphone and watch tik toks.

Btw, a ghost is the lingering remains of a “soul” who has died but was unable to move-on to the “afterlife” due to regrets, unfinished business, or a traumatic death.

A spirit is a different entity- they were never living humans to begin with- they are an energy species that can interact with the physical world and remain intangible themselves. They do not share the limitations of ghosts.

I apologize. Thanks @Ikara for clarifying:

Ghosts aren’t real so there are lots of rules. Clearly this inconsistency has been hashed out and tempered into a criticism-proof system of belief.

2 Reasons:
1. It’s the movies so they can make anything they want even it doesn’t make sense.
2. Flawed people (writers, editors) results to poor story lines with inconsistencies.