Keep pulling on it till it stops, you may be able to look inside with a flashlight, see what, if anything, it is connected to. The grommet in the wall doesn't appear to be large enough for the plug to pass through. The other end likely the same. The cord would need to be cut, inserted into the hole, then connected to something on the other side, requiring access to that back side.
Might be a factory install.
Any mention in the owners manual?
Region 3 , 1st VP
Go often to the house of a friend, for weeds choke the unused path........Emerson
Never pick a fight with an old man. If he is too old to fight he will just kill you........a wise old man.