A ghost is read as the past still present: a memory, a regret or a person not fully let go. It traditionally stands for something that wants to be acknowledged. The ghost of someone you knew is read as love and grief still at work, not as a visit from beyond. Being haunted in your own home points to an old pattern or feeling that keeps returning, while being a ghost yourself suggests feeling unseen or left out. A friendly ghost is taken as peace with the past. Dream books ask what the ghost seems to want.
Has this come up in your dreams before? What was going on in your life then?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.