Was It Really A Ghost?

I woke up in the midnight. All the lights were off. I got up from my bed and headed to kitchen for a glass of water. In the midway, my right foot stepped on something, something very gooey, sticky. Just like glue....or blood? I thought it to be a mop. I turned the lights on, and to my confusion and surprise, there was not anything on the floor, nor on my foot. I drank water from the kitchen, and headed back to bedroom. In the midway, I found the lights of bathroom to be on. I could swear they were off just a few seconds ago. I knocked the door.

"Brother, is it you?", I asked, my voice shaky.

"Yes, it's me.", said a deep rumbling voice from the other side of the door.

As soon as I went back to bedroom, I couldn't believe what I was seeing— my brother was fast asleep. I rushed back towards bathroom. This time, the lights were off. It took great deal of courage to open the door. But, no one was inside. A shiver ran down my spine. I turned back to see my brother standing there. I couldn't believe it, he was in the bed just a few seconds ago. How could he get there so fast?

"Hey, it's midnight, go and sleep.", said my brother.

I did as I was told, but only I couldn't sleep. And how could I? And just when I was about to sleep ( after half an hour of turning, and sitting up, and again laying back), I heard a giggling sound, almost ghostly. I was already afraid. I dared not to open my eyes. I knew my parents and brother were asleep. I tried to concentrate my mind on sleeping. But, I couldn't. And after listening carefully, I made out that the giggling voice was coming from the balcony. I got up, mustered all my courage, and headed to balcony. I opened the door quietly, and went out. Nobody was there. The giggling voice had stopped, too. Maybe I was hallucinating. So I decided to breathe in some fresh air. And just then, I heard the door closing behind me. I ran to the door and started knocking it. The giggling voice had started again, this time just behind me. Sweat broke out all over my body as I continued to knock the door. After a minute or two, my dad opened the door. The giggling voice stopped just then.

"What happened? Are you okay?", my dad asked.

"Sleepwalking. The door closed.", I said. 

The next morning, I woke up and everything seemed normal– my brother, the bathroom and the balcony. I dared not to tell anyone anything about that night. 

Even today, when I recall that night, I get goosebumps. I will be really grateful to you if you can tell me what exactly happened that night.