Mysterious Markings...

OK, so ever since my parents bought the home they currently live in, us kids have all thought it has a ghost in it. The original owner sold it to my parents after his wife passed away. I think the ghost is her. Weird things have happened throughout the years, too many to tell... but VERY strange, unexplainable things. We were over there on Sunday and Derek walked into my facial room and it was completely dark. He folded his arms and said, "Scared... ghost." We don't know how he knows about ghosts because we haven't ever talked about ghosts in front of him. I thought that was a little strange. Later that day Derek woke up from his nap and he had bright pink marker all over the right side of his face and arms. Not just a highlighter, but dark, bright pink marker. We don't even own a marker that looks like this. He has wrote on himself before in bed (not sure how he finds the pen!) but usually it would be all over his sheets too. It was only on him. I searched for this marker EVERYWHERE! No where to be found... I mean we had 3 people looking... not in his bed, not under the bed, not tucked between the sheets, not anywhere in the room! So Jamie said, "Maybe it was the ghost!" I thought... hmmmmmm, maybe. My mom wants nothing to do with this 'so called' ghost. She freaks out every time we bring it up. We all think she does this because she knows the ghost really does exist. So when we got home last night Jason gave Derek a bath. He scrubbed and scrubbed but the marker wouldn't come off at all, it didn't even fade a little bit. Now Derek has gotten permanent marker on him before and I've been able to scrub that off! So he went to bed and when he woke up this morning the marker was gone! Completely gone! There was no sign of it rubbing off onto his pillow or sheets... NOTHING! Pretty strange. My mom cleaned his room at her house today and found no marker. So anyway, I just don't know why the ghost would write on him with magic marker that disappears the next day! I'll keep you posted on any other ghostly experiences.