I think we have had discussions on this topic. I'm like the OP in that I don't fully believe but I'm not completely opposed to the idea. I do remember when DD was around 6 months old we were visiting my grandmother and DD was in her exersaucer in the living room but kept looking towards the kitchen and saying Mama but as a question. I tried to get her attention but she kept going back into this haze and repeating her question about Mama. I never thought anything about it but I guess it freaked my grandmother out since she contacted the priest and he came out and blessed the house. To each their own.
Then when DD was around 16 months we lost my grandmother but the day before she had her massive stroke we had visited and DD was over the top all about her 'Nana'. She didn't want to play with anyone else and just wanted her. Perhaps she sensed something wasn't right? After my grandmother passed away and we had moved into another house we had some interesting occurrences with DD. She insisted that her 'Nana' was there with her. Sometimes she was on the bed and sometimes floating in the corner of the room. She was never frighten because it was her Nana but she was emotional because she clearly missed her. Did she have visits from my grandmother? I, personally, don't believe in it but I do believe that if it is possible my grandmother would be there in a heart beat since DD was her pride and joy.