Fort Erie, ON
CHCH runs on physical UHF 15 even though the virtual channel is 11. It would be impossible for you to be getting 15 out of Buffalo up in Grimsby, as it's a digital LP and the signal doesn't go anywhere beyond the inner part of Buffalo and Fort Erie. You can't even get it in Niagara Falls. What you're probably seeing is 26 out of Jamestown with a virtual channel of 15 assigned.