A four-year-old girl named Sidney Fahrenbruch recently moved into a new house with her family in Longmont, Colorado.

And she started hearing weird sounds at night . . . so obviously she thought the house was filled with monsters.  But now she’s absolutely sure there AREN’T any monsters!! A local cop helped her sweep the entire property last month.

Officer David Bonday talked to her at a recent community forum and offered to help.  She got to wear her own police uniform, and he gave her his flashlight while they walked around the house . . . checked the closets . . . and looked under the couch.

He even checked outside with her, because she thought they might be hiding under the bushes.

Now her mom says she’s totally fine living there, and wants to be a cop when she grows up.