Combine the cubed squash, milk and chicken broth in a saucepan. Season with salt, pepper, curry powder, celery salt, cinnamon and nutmeg. Bring to a boil, then reduce heat to low, and simmer for about 30 minutes, until squash is tender, stirring frequently to prevent the milk from scorching.
Add 1/2 the shrimp, and 1/2 the pears to the soup, and bring to a boil. Cook for 5 minutes, or until shrimp is opaque. Transfer the soup to a blender or food processor, and blend until smooth. Return to the saucepan and bring to a simmer over medium-low heat.
Add the remaining shrimp and remaining pears to the soup, and simmer for another 5 minutes, or until shrimp is opaque. Stir in sherry wine, and remove from heat. Ladle into bowls, and garnish with a light sprinkle of cinnamon or nutmeg.
