It May Not Be Ghosting

Due to what I've read in here. This may be just me, but depending on the context then a few days to one week isn't ghosting. Unless you're steady with them or they're family then replies within one to a few days is too high of an expectation.

If they're "a friend" or "someone you're seeing" then they have other stuff going on. This may be something bad, or it may be something irrelevant to what you have going on with them. But you can't expect them to put you first at this stage.