Fireplace goes on/off
We have the same issue.  There is a pilot light. Runs on LP.  Pilot does not go out but the flames go out and then in a little bit it comes back on.  No other light switches are being turned on/off and there is no battery in the unit.  We found that when it is turned at a lower setting it happens far more often.  But it will go from flames 8 inches high to off in 1 second and then after about 2-3 minutes it comes back on.
If we turn it to a higher setting the problem goes away and the fireplace stays lit.  Because the pilot doesn't go out we know it's not air in the lines or a main regulator issue.