Hide and Seek at Grandma's House

This story is really creepy... it's something I experienced when I was young. I went to visit my grandma's house during summer vacation. It was a big house in the countryside, and for someone who had only lived in apartments, it was really exciting and fascinating. That day I was playing hide and seek with my cousin who was 2 years older than me. At first, my cousin was "it." "Ready or not?" my cousin asked. "Not yet~" I replied. "Ready or not?" "Not yet~" I slipped and hid under the blanket in the main room. I thought it was the perfect hiding spot. "Ready or not?" "Ready now~!" My cousin's light footsteps got closer and farther away. They'd get farther then come closer again... I held my breath and listened carefully. After a while, my cousin's footsteps came toward the main room. "I can see you! Come out quickly~" It seemed like my cousin had found me. But I stayed still. I had been tricked by such words before and came out only to get caught. "Come out quickly~" I kept ignoring it. "Come out now! I found you but you keep doing this, I'm getting mad~!" My cousin's voice gradually became more angry. That's when I peeked out from under the blanket... My cousin was slightly opening the main room wardrobe and talking to someone. "I know you're inside but you keep doing this! You really don't listen!" And then my cousin put their hand into the wardrobe and started pulling on something. Thinking it was strange, I came out from under the blanket and shouted. "Cousin! What are you doing!" At that moment, my cousin looked at me with a startled expression, screamed, and quickly pulled their hand out of the wardrobe. Then started crying loudly. "There, there was definitely someone in the wardrobe... I definitely grabbed a hand..." My cousin had grabbed that hand thinking it was me. In the evening, adults came and checked inside the wardrobe, but... There was nobody inside the wardrobe. But what was really strange was that for several days after that night, strange sounds kept coming from the main room. It sounded like someone scratching from inside the wardrobe. Grandma said it was "the sound of wood contracting because the house is old," but... we knew. What my cousin grabbed that day was really someone's hand. Even when visiting grandma's house after that, we avoided that main room. And I never went into that room alone. Even thinking about it now gives me chills. What was really inside that wardrobe back then? And... is it still there now?