My Daughter Sees And Senses Spirits

I am just looking for some insight into how to help my daughter with her fear of ghosts. I know it is a normal reaction to be fearful, because I too am frightened when I see things that I can't explain. She often sees images in her minds eye of ghosts, one in particular I believe to be my grandmother who passed several years ago. When she was very young (she is currently 9), approximately 3-4 years old, she had two "imaginary" friends that she used to play with. One was very friendly and sweet and the other was quite mischievous, often causing my daughter to scold it. She no longer sees these two friends, I believe because we moved to a new home, but now she is seeing and hearing other things. She tells me that she often hears voices while she is laying in her room, and that she sees images in her mind. Both of my children stay at home during the day now that school is out for the summer and they will often call me to tell me that they hear noises or that the lights will go on and off by themselves. My husband has zero tolerance for talk of ghosts and doesn't believe they are possible, and he often will dismiss their accounts and scold them for believing in ghosts. I myself know that they exist because I have seen and felt them before, but to keep my husband from becoming upset, I am also forced to tell my children to dismiss them. My question is, I know ghosts are real, my kids know ghosts are real, how do I go about acknowledging their ability to see them without frightening the daylights out of them or irritating my husband. Any suggestions are appreciated.