Why is my 5 year old granddaughter so scared, she wont sleep alone?

i take the dogs out and she hide in the bathroom. when i let the dogs out im just outside the kitchen door, and she right here in the open concept kitchen/family room. she wont even go play in her beautiful room by herself.she has every thing in it that she want big three story doll house,that she never play with. she live with me, i kinda think when she lived with her mother, she watched to many scary movies. It is really starting to bother me, because i keep trying to explain to her its nobody in the house but me her and papa. when she did sleep in her room a couple times she had my husband sleep on her floor and he did it like a fool. who should i talk to im tired of her in my bed. im not going to make her sleep in her room, because to watch her i know someone or something has scared her. Any ideas?