Sign is related to Danger. Danger is related to Warning. Warning is a form of Warn. 
you are likely to find Dirty in/at/on Bed. you are likely to find Scary in/at/on Bed. 
Sign <--RelatedTo--> Danger <--RelatedTo--> Warning --FormOf--> Warn 
Dirty --AtLocation--> Bed <--AtLocation-- Scary 