Grandmother's house represents a feeling of security and safety, warmth and love.

Knocking - suggests that your subconscious is trying to attract your attention to some aspect of yourself or to some waking situation.

Monsters - represent not so much a situation as a person in your life. One that you feel threatened by, or scared of. Adults(known or unknown) that yell or punish a child could be represented as monsters in the dream of a child.

Chased - In this dream you are usually being chased by some villains, monsters or criminals who wish to harm you. But often these pursuers represent current tensions and issues rather than actual people. This dream usually shows the level of stress you have at the moment, and is a signal to take control over the worries and resolve issues with a clear head.

Alternately, you might be trying to avoid something. Identifying what, or who, the chaser represents might clarify what you're trying to avoid.  If the person or thing chasing you is identifiable as a part of yourself, the dream might involve a fear from within, such as an unhealthy relationship or unhealthy behavior.
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Monster and chase dreams are common in children. Seeing something on tv, being punished by an adult, or being startled by a pet, or another sibling could cause these types of dreams.