Earlier quoted context omitted.
Do you have a citation for that?
Sure. This is the relevant clause in my current home insurance policy: "You must take steps to maintain the Home in a good state of repair and take all reasonable precautions to avoid loss, damage or injury and to safeguard all property insured from loss or damage." These things are pretty standard - I would be very surprised if there isn't a similar clause in all of them. Which implies that, if you fail to do so, th…
For completeness, the relevant section from my policy is "We will not pay for any loss to the property...as a result of...Neglect, meaning neglect of the insured to use all reasonable means to save and preserve the property at and after the time of a loss, or when property is endangered". But in the same context, it says "However, we will pay for any resulting loss from ... defect, weakness, inadequacy, fault, or unsoundness in ... design, specifications, workmanship, repair, construction, renovation, remodeling, grading or compaction; [or] maintenance."
It would be shaped by the legal precedent in interpreting these sorts of clauses, and perhaps also the whims of a jury. It still seems unlikely to me that either of our policies would end up excluding the electrical anomaly, and moreover I've yet to ever hear a verifiyable account of someone whose homeowners insurance claim was denied after an electrical problem in their house led to a loss.