Jehovah's Witnesses Zone
A long stretch of houses (at least one block) without any Christmas lights, the absence of which suggests the possibility of there being a large concentration of Jehovah's Witnesses living in that area.
Person 1: Do you want to drive down that street?
Person 2: Nah, nobody has any lights up; must be a Jehovah's Witnesses Zone.
Person 2: Nah, nobody has any lights up; must be a Jehovah's Witnesses Zone.