My one year old female started urinating in the corner of my dining room near the window that faces the back yard after a stray cat started hanging around in the backyard. My cat would sit in the window & hiss & growl at the stray cat. I put miniblinds up so she can't sit in window & cleaned carpet, but she continues to urinate in that corner. She is spayed & has never done this before.
Try feliway, which helps to relieve stress. Clean the soiled area with natures miracle. Good luck, vetcare