Old houses are required to have a mystery light switch to keep the ghosts occupied.

There is a chance that if those are lights beside the door, they were installed and just lazily trimmed over. Meaning there is no way to access the bulbs without tearing apart the trim. Personally, I would find out it if the switch has power coming to it. Then replace the entire entryway and install a proper porch light that is powered off the switch. It will look better and ensure things are done right.