My 13 year old daughter had a short term illness when she was 4 years old shortly after my father (her grandfather) had died. I was holding her in a family room chair and she started giggling and pointing up at a step into the kitchen. I asked her what she was laughing about and she replied, "It's Poppy (her name for my father). He is so funny" I asked her what she saw and she said, "It's Poppy, he's right there" I didn't say anymore to her of it at the time, but she still recounts the experience now.
Recently, she has been seeing a man who she describes quite elaborately, down to the clothing he is wearing, who appears at her school and is in the same place in a corner of a hallway she passes each morning. He is standing and sometimes gesturing to her in a wave or a shoulder shrug.
One time he was trying to tell her with his arm gestures to turn around for some reason. One time her great grandmother was with him. (She died within the last 2 years) and one time the same grandfather (Poppy) was with him. I asked her how she responds to him and she tells me that she smiles and sometimes waves discreetly, because middle school friends are around. She says that when she looks away after seeing him, he is not there when she looks back.
She has not seemed fearful or negative toward the experience, but is rather, interested in who it is and why he is there.
We talk about her day every night at bedtime and some nights I ask her if she has seen him. She answers yes about half the time.