Can children see ghost or is this a hallucination

I'm on the fence about this subject.
Part in being that I believe there are forces around us that cannot be explained, and I've had many personal experiences seeing and feeling things that cannot be explained.

I also am aware that severe depression, & bi-polar disorder can also cause someone to have hallucinations.

So I'm at a quandry, a fork in the road...What do I believe is happening to my child?

My son is 10, and as you know from earlier postings we are dealing with his depression at this current time. He recently told me that he feels, and see's ghosts. He says there is a lady upstairs, she is older thank him, is wearing a long dress with long sleeves, has her hair in a bun, and she has blood on her shirt. He says he knows she died from a car accident, she doesnt want to hurt him, she wants something from him, or to tell him something, but the sight of her scares him.

Now, on his defense, we have strange things that go on, all of us, and others who have lived in our home previously have had an encounter of one kind or another. I have had the bottom of my feet tickled, All of us have heard deliberate footsteps walk upstairs from one end of the house to the other, electronic equipment going off and on, feelings of being watched or followed, or just an overwhelming feeling that someone else is here that we cannot see. Acticles have been moved, hidden, or unable to be found, when we have been sure of where they were, and even "tested" this theroy.

BUT how do I know if my child really sees something, or is having hallucinations? This is a subject that I'm going to do more research on.....

Who knows, maybe I am crazy myself for even entertaining this subject.

Its been weighing on my mind, I'm fearful that he is having hallucinations. what do I do then? And what kind of therapy will be reccomended?