Who is Knocking on my door?

I sat with my legs folded, enjoying an episode of the walking dead. 
The episode was just about to finish, and I was a bit tired.
I looked over at my little sister, who was already knocked out, but my little brother was wide awake.

My mother was out at work, and was due to come home soon, but I couldn't wait up anymore.
I shut the television off and went to bed, ensuring that my brother and sister came along with me.
After tucking my siblings in, I realized that I had forgotten the kitchen light on, so I went downstairs to turn it off.

Walking out of the kitchen, I was startled by three loud knocks on the front door.
Normally I would see the shadow of anyone who stood outside the door, but mysteriously, there was none.
I stood at the bottom of the steps for a while wondering if I should investigate.

I heard the Knock again, but this time it was heavier.
I walked slowly towards the door, my eyes fixed on the glass area of the door.
"Mom!" I called out softly, hoping that it was her.
I didn't get a response, and I got this weird, churning feeling in my stomach, something was not right.

Suddenly, it was like I heard footsteps behind me.
When I looked down, wet footprints, were evident right behind me.
I held my mouth tightly, wondering if I should run upstairs and tell my father.

My heart started racing uncontrollably, and my brow was slowly filled with sweat.
The knock happened again, once I got closer to the door, but this time it was repetitive and it didn't stop.

I pushed open the door, and there was no one there.
I quickly locked the door, and ran up the stairs.
Once I got on the the third stair, the atmosphere immediately grew cold, and a warm hand touched me.
I glanced back and I couldn't believe it, a female figure, casually starring at me.

"Dad!" I screamed.
"Dad!' I yelled.
He ran to my rescue, his face, so confused.
"What is it?" he asked, looking down at my shrunken body.
"A ghost," I uttered softly, reaching for his hands.
My father looked all around and found nothing; "Come on, you probably just need to rest."

Momentarily I looked back, in hopes that the ghost would appear again, so I could show my father.

Was I going crazy?
Was there even a ghost?

So guys, I am a Romance Writer, and I'll like to start doing thrillers soon.
Please, leave some feedback. Do you think I'll do a great job?