This definitely could be probable cause. When I was a teen I witnessed such fire once. Basically a friend had a heater but couldn't find any mains cable and eventually decided to disconnect mains cable from the radio and use that. After few minutes the isolation from the mains cable melted away and the cable turned glowing red and it started burning the table it was on. Fortunately we were not asleep and got it under control quickly. Lesson learned.
