12yr son scared of our basement because everyone thinks he saw a man down there

Not everyone** that was autocorrect. He is the one that is seeing the man down there. Our 12 yr old son is scared of our basement. I thought maybe he was a little too old for this one but we learned that he is too scared to go down there because he “saw” someone in the basement yesterday.We were all eating dinner and I told him to go get something out of the basement, so he did. He opened the door and was down there for at least 10mins then ran back up and said he saw a man standing in the corner in our basement. The basement light was on and he could see everything but he was truly convinced there was a man down there. So my husband went down there and looked around and there was nobody there. I explained to him that our eyes play tricks on us sometimes and make us see thinks that aren’t really there. He agreed. So he went back down there to get whatever I said get because he didn’t get it the last time. So he went back down there. The rest of the family was in the living room watching tv and he ran back up saying he saw the same man again. I asked him what he looked like he said very tall, gray hair, black clothes. I told him to come down and that he was just seeing things. He got mad and said I’m not seeing anything! He said he saw a man and heard noises down there. And now we’re arguing. How do I handle this situation? via /r/Parenting https://ift.tt/32sz1mK