Do You Believe in Ghost Spirits?

[Nosherwan]

@SargeCandy

You never say salam to graves when you come across a graveyard?

When Nabi Kareem Sallallahu Alaihi passed near graveyard of Madina Munawwarah then he said:

“Assalam O Aalaikum Ya Ahlul Quboor Yagfirullahu Lana Walakum wa antum salfuna wa nahnu bil asari” (Mishkaat - Baab Ziaratul Quboor, Tirmizi)

Yes but how does that prove that they are not in Barzakh but roaming the earth like ghosts in western culture?