[Jlesnik33]

This might seem a little random, but how would I know if there is a ghost in the house, or if it is just in my head?

[Capuchin]

Ghosts are not real, so probably just in your head.

[Jlesnik33]

Then how are there sightings?

[Capuchin]

It's mostly stuff in people's head, or exaggerating normal things such as wind etc. They don't see a ghost, they see something that they interpret as a ghost. The brain can get confused, especially in times of grief or stress.

Despite interest in ghosts for many hundreds of years, there is really no evidence that they are real.