The Sects of Atheism

[Mister Agenda]

If someone doesn't believe in gods, why would they believe in any other supernatural thing?

If someone didn't believe in the supernatural, it would follow that they don't believe in any gods; but it doesnt' follow the other way around. For example Buddhism doesn't really feature a creator God and belief in lesser godlike beings is optional in some sects. The few Buddhists I've met who would describe themselves as atheists AND believe in reincarnation take the cycle of reincarnation to just be part of the nature of reality, not something invented by a god. Even in theistic versions of Buddhism, the gods themselves are subject to reincarnation.

Not to mention I've met atheists who believe in things like astrology, ghosts, and homeopathy.

My own path to atheism involved increasing skepticism, I stopped believing in Bigfoot and ghosts before I stopped believing in God. Someone else might just not been raised to believe in God in the first place but also not have been raised to be skeptical, or find astrology easier to believe than the gods they've been told about. Maybe someone who believes in ghosts but not God thinks they've seen a ghost.

Could be lots of reasons.