Give a stream of consciousness and then the final answer. Although set in "Middleton, USA", it was filmed in Hamilton and Niagara on the Lake, Ontario. In the sequel, The Good Witch's Charm, the map on the wall in the police station shows Middleton north and west of Chicago, in the vicinity of DuPage County. The names of the suburbs and interstates that are west of Chicago can be clearly seen.

Based on this passage, where is the hallmark series good witch filmed?
To answer this question, we should know that: Although set in "Middleton, USA", it was filmed in Hamilton and Niagara on the Lake, Ontario.
So, the final answer is Hamilton and Niagara on the Lake , Ontario.