My kitty Gibbons began spraying when a stray Tom started showing up around our yard. He loves to sit in the window and watch the world go by, and saw the stray out there one day. He only sprayed one area, and we ended up having to ban him from that room and cleaning everything with an enzymatic cleaner to kill the smell. Gibs was neutered at 6 months of age, as a side note.

Is it possible theres a stray hanging around thats got your kitty in tizzy?