Is It Created Spirits That Cause This?

Created spirits that we are aware of fall into two categories, human and angelic. Angelic spirits would seem to have the raw power needed to cause some one to burst into flame. We don't know enough about the powers that disembodied human spirits may have. Would good spirits, like angels and saints want to cause this? Not unless god wants them to. On the other hand, demons aren't limited in their activities so it's easier to see how they'd have the liberty to cause a problem like this. But causing physical problems isn't what demons are primarily interested in. And i'm not aware of any good evidence linking demons to it.