A ghost knock my house door three time

This is a true story of my ghost encounter.

It is happening at the night in front of my house, my parent is working. I was playing with my cat name Doona. My cat likes to play with the laser. It always makes me feel happy. After it feel tired I stopped play. My cat is hungry so it already went inside the house quickly. Before I went inside I have to lock the door
SUDDENLY....

I saw something like people with white clothes, the ghost walked then suddenly flew across my neighbour's house so I fast as the flash run inside the house. I took the blanket and hid in my room. My sister suddenly came to my room and make me calm down. My sister ask me to tell her what happened when I tell all the stories... SUDDENLY MY DOOR WAS KNOCKED!

so my sister asked me to see who was knocking the front door. So I came down and opened, there was no one there. So I said in my mind I think that is that ghost ..but my! my! sister
don't believe that. My sister said.. who was outside then I said, my friend.

SUDDENLY THE KNOCKING CAME AGAIN! So my sister said is that your friend knocking again? Then I said do not know with
a worried face so my sister said let me open the door this time. So my sister came to open the door but then NOBODY OUTSIDE. So my sister came back with a fearful face.

THEN THE DOOR WAS KNOCKED AGAIN!

So my sister said don't open! We run to our room and started praying.
We really run so i fast like tiger to our room. The next day we both told our parents but our parent can't believe that......