Oldsmobile/Buick Repair: Electrical on 97 Old Cutlass Supreme, cutlass supreme, different gear

Question
The reverse lights are continually on regardless of whether the car is on or not.  This drains the battery (obviously).  

What should I look at to repair this problem and is it a major repair (ie costly)

Answer
On top of the steering column, above the brake pedal, there is a switch, which is also the neutral start switch. It is adjustable, but yours may be bad. But I would try adjusting it first. Especially if the reverse lights go out if you put the car in a different gear.
Van