How did a vinyl record start a fire?

Records are actually not known to be, in and of themselves, flammable. However, if you coat them with something flammable, and then seal it in to keep as much there as possible, then that is maybe a whole other story. Here is what I might try that could work.

1. Spray your record down with with an acrylic coating like Crystal Clear from Krylon, or Mod Podge to create a super thin, but protective base. Or even an enamel coating like Rust-Oleum. Anything non flammable to make a fully sealed barrier between it and the record.

2. Then use a lacquer (lacquer is highly flammable) that is properly mixed as to not eat away at plastic. Keep in mind, you have already given this a sealed coating to help this out. I'm sure any paint store could suggest a proper plastic safe lacquer. They do exist. Just make sure it is still highly flammable as well. You want the flame!

3. After lacquering it up, then hit it again with an acrylic or enamel coating to seal it all in, thus creating a flammable sandwich filling between two slices of enamel bread. All three of these are in fact clear by the way, thus you would never know it has all this on just by looking at it.

4. Now make make sure your tone arm, running all the way down through the head shell to the needle (stylus), is metal. This is what is coming over and playing the record.

5. Now just clamp on something that will make the metal overly hot when you start it up and that current runs all the way along the arm down the needle so that as it runs along the groove, it will easily push through the protective enamel barrier to ignite the highly flammable coating of lacquer, thus setting the whole record on fire.

I'm not sure exactly what this would be, I imagine batteries, or maybe rewiring it with a garbage low watt cord that can't handle the power needed safely. Think like when you plug in a space heater, set it to high, and the cord starts to get really hot and can potentially set the whole device on fire. That is what your going for here.

You can even buy a record player that would play the record at a certain time, thus setting it up in advance to burn down your house. Such as the ADC Accutrac 4000. A turntable that factored into a murder on a 1977 episode of Columbo Season 6: The Bye-Bye Sky High IQ Murder Case

I honestly think this could work if someone tried it. (Probably shouldn't try it)

Hope this helps.