Here is a scary answer, it depends on property owner. During one of my inspections today, I had what was supposed to be a sweep only of a fireplace at a vacation rental.
To start, I refuse to ever do a sweep without an inspection, even if the homeowner insists that they only want a sweep of the system. Upon initial inspection, here is what the renter would see (and probably think it was safe).
During my initial inspection I started noticing immediate red flags and started inspecting further. After ten minutes I had found that the flue liner was deteriorated, combustible debris was inside of the exterior metal surround, and the liner had disconnected towards the top of the system!
Using a fireplace during a vacation can be a relaxing experience and create a wonderful ambiance during the holidays, but can also quickly become a serious safety issue.
In summary, be very cautious with a fireplace that you have no prior knowledge of. Look for things such as current fire extinguishers and smoke/carbon Monoxide Detectors before considering using the system. Lack of regulation is the biggest challenge we face so when in doubt, don’t use it!