Officers said the boy was not injured or molested.
The incident happened at the Interfaith Apartments on W. Fifth Street in Richmond.
Officers said the boy was met by the masked man in the stairwell of the apartment building and forced to strip naked. They said the man then led the boy outside and took off, leaving him alone.
Police said the boy began knocking on doors for help and was able to call 911.
Lt. Brad Berner said the apartment building is home to mostly senior citizens, but there are some residents living there who have mental problems.
Investigators are in the process of interviewing those residents.