Hello and welcome to JustAnswer!
The interior light problem could be a handful of things. If the body control module is seeing a door open then the lights will come on, but you should see the door ajar light come on at the same time. It could also be a BCM problem; either of these two situations aren't as likely.
The most common cause of interior lights or headlights coming on by themselves on one of these cars is the headlamp switch or voltage bleedover in it's connector. The first thing I would recommend is applying some dielectric grease to the headlamp switch connector. If that doesn't take care of it then most likely the switch will need to be replaced.
The cruise control
problem could be a handful of things. It could be a bad brake
switch, cruise servo, wiring problem, switch or clockspring problem, or it could be seemingly unrelated issue. If a fault code sets regarding the MAP sensor, throttle position, vacuum leak, a cam or crank sensor code or a few transmission
related codes can prevent cruise operation. With the check engien light coming on at the same time the cruise stopped working the problem is pretty surely related to the light being on. The first step in diagnosing the problem is going to be reading the fault codes and that will give a starting point for diagnosis.