I had this happen recently as well...twice. Once to a wood stove & once to a fireplace. They were both upgraded with fireguard but not auto-light. For the wood stove, only the wood floor caught fire (fire2 image); I added the cement paver from GT underneath & a stone wall behind (stones image), thinking it was the wood floor or walls causing the fire. For the fireplace, the sofa & rug caught fire (fire3 image) despite a stone wall & built in cement hearth. Maybe the furnishings were too close, but it's a small house & i had hoped that the fireguard would...work? My sim lived in the Cozy Corner House (renovated) in Chestnut Ridge. The active lot traits/challenges at the time were Peace & Quiet, Private Dwelling, & Simple Living; the active NAP was Back to the Old Days. I don't need a reply as I'm now playing in a different generation's house...just thought my info might be helpful. Good luck! Edit: I do have For Rent, but am not currently playing it and have not had a recent cursed book event.
