Wrong Person Buddy & Rude Awakening

First of this hapened to my younger brother Nestor about a month or so ago. He didn't want to tell me about it but my mom brought up the subject in a conversation we had a couple of days ago.

My brother was sleeping late in the morning since he was woken up by the sound of the front door opening and closing downstairs. He thought that it was my other brother Axel coming home from work so he just ignored the sound and tried to go back to sleep. He heard Axel go up the stairs, walk up and down the hall, then he heard him lay down and his bed. Now my brothers have a bunk bed and Axel sleeps in the bottom one and Nestor sleeps on the top. Nestor thought that it was strange that Axel had not spoken to him when he came in the room so he calls out "Axel what are you doing home so early from work?" All of a sudden he says that this deep voice answers him from the bottom bunk "wrong person buddy". Now my brother freaks out thinking that somebody broke in the house so he jumps of his bed to see who is laying on the bed but there was nobody there. He gets this really weird feeling that someone else is in the room with him, so he grabs his car keys and cell phone from his dresser and he runs down the steps, gets in his car and goes to my mom's job.

He finds her and he tells her what happened, he is so freaked out that he doesn't go back to the house until my mom is with him.

Needless to say my brother will not stay home by himself for long after this happened. My mom also told me that two weeks ago she was sleeping when all of a sudden she was shaken awake by something, she was so scared that she screamed and woke up my stepfather. She told him what happened and he searched the whole house but found nothing. Mom did not sleep for the rest of the night, she told me that she could feel something "bad" was in the room looking at her.