Your story a bit unbelievable
Ghost exists but you hardly see them in human form ... I means you only able to see them in white or black shadow ...

I recall those tvb Guai Tan and the sifu sifu said it's do appear in human foam and can change face as well but that is Super Ghost which mean need a Lot power and this is not call ghost but devil ..

This kind of ghost need to "kill somebody to accumulate the power .. example purposely tarik your kaki during swimming and mati ...