Believe it or not, this is a classic indicator the light was turned on by the remote. A "Search" on Security or Scare light will point out numerous occurrences of this phenomenon. When the light has been turned *ON* by the remote, it can *ONLY* be turned *OFF* with the remote
You wrote "The remote control does not work". I take this to mean you have the remote. Replace the battery (one screw for the cover may be hidden under the label) and give it a try. As a last resort you can remove *ALL* power (120V and 12V) for 10 minutes and the control brain may forget about the light. Otherwise find the "brain" in the front compartment and remove the wire for the light circuit (a Search should give you a picture of the "brain".
Fixing the remote is the quickest way to solve the problem. Then if you don't plan to use the remote in the future, remove the battery so this won't accidentally occur again.
On Edit: The hitch light is on the same circuit DS scare light which is why it is on too. Here is a picture of a "brain". Yours may/will look slightly different.