Witchipedia

I can't find specific symbolism for a flaming pentagram, although perhaps someone more knowledgable than I may come to your aid! Only you can interpret what it means. The best course is to look up the symbolism for fire and see what might explain it.
For example, 1) fire is warming and powerful - so it can be a positive affirmation. 2) It is also destructive and brings death - is someone trying to put you off your practice? Does someone important disapprove? Freud believed that fire represented hidden desires which, if combined with the "death" meaning would suggest you feel repressed and unable to express yourself.
Fire is the only element that man can make for himself, so it is seen as a link between humans and the gods. Even if the connotations at 2) above seem to ring true, the fire itself is a sign of your desire to connect spiritually. It is certainly not a bad sign. Also, on a more practical and mundane level, have yet ur eyes tested regularly - seeing lights or fire when your eyes closed can be an indication that your eyes are in need of attention, specifically your retinas. (That's a medical fact, not a craft belief, by the way). Blessings.