booby trap
noun
a hidden bomb or mine so placed that it will be set off by an unsuspecting person through such means as moving an apparently harmless object.
Used to describe actions that started in the past and continue into or have direct relevance to the present.
Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.
They must have booby-trapped the place against intruders.
From The Secret of the Ninth Planet by Donald Allen Wollheim