I do not believe in ghosts.

Here's why.

There is no objectively verifiable evidence for their existence. None.

The only "evidence" anyone has ever been able to put are horrible quality blurry video or photographic recordings, or claims from eyewitnesses.

As to the first, is it so easily faked, so this cannot be considered.
As to the second, there are numerous explanations why someone would make the claim. Anything from intentionally lying, to delusions, hallucinations, or general confusion. People claim to see things all that time which aren't real. I met a guy once who saw the cast of the Mortal Kombat video game in real life as part of his schizophrenic delusions.

If you want to prove the existence of ghosts, you need some kind of independently verifiable experiment.