Dreams involving deceased loved ones can evoke strong emotions and often carry significant meanings. In your dream, your late grandmother's promise of returning may symbolize a longing for connection or unresolved feelings related to her passing. The transformation into a ghost could represent your fear of losing that connection or perhaps anxiety about the unknown aspects of death and the afterlife.

This dream might be your mind's way of processing grief or expressing a desire for comfort and guidance from your grandmother. Waking up scared suggests that there might be underlying fears or unresolved issues that you need to address.

Consider reflecting on your memories of your grandmother and any feelings of loss you may still be experiencing. It could be helpful to engage in activities that honor her memory, or even talk to someone about your feelings. This way, you can find comfort and closure regarding her passing.