This phrase is often used to describe the cause of irrational fear, especially at night.

Fear Inducer

Children's stories or experiences may refer to this phrase to describe monsters under the bed.

Child's Imagination

Emphasize that the phrase refers to imaginary fears, not actual dangers.

The phrase is sometimes used to rationalize strange noises at night, suggesting they're not harmful.

Often related to the creaks and groans of old buildings at night, which can sound eerie.