I returned to my camp, afternoon of day 17 to find this mini fire, burning.
At first I thought it was a graphical glitch from the fire pit, and thought nothing of it.
However, when night came, I realized it gave off light, and never stopped doing so!
I have no idea how this happened, but the fire seems to be similar to one of those started by the "firestarter" character I've been messing around with recently.
If I or someone could figure out a way of replicating this glitch, you could switch to firestarter, produce an infinite light source, and switch back to whatever character of your choice!
I'll keep you all updated on anything else I find relating to this.
Feel free to respond with any other tips or hints regarding producing an infinite flame of this sort or any other sort!