Windstar electrical components staying on

I have a 2003 one owner Windstar, 165K miles. in the last three weeks I have started to have these problems: external reverse lights staying on after car is shut off and when driving. Then the high mount stop light (brake light) began to stay on after vehilce is shut off, then this week the rear heating/AC unit fan turns on & off while driving when switch for rear control is in off position.

Battery died and replaced with new one before I knew about this problem. Alternator is less than one year old.
Less than a year ago vehicle was in front end collision that damaged mostly rt ft fender and bumper, lights & harness.

I replaced the Neutral Safety Switch but the reverse lights stayed on anyway. I checked the socket for the high mount stop light..it is good and bulb is good. I dont even know what to check on the rear heat/AC issue.
Something major electrical is beginning to happen and I need ideas. Could it be a fuse block/corrosion problem? HELP!

You may have one, or both of the following: Shorted lamp bases ... remember this vehicle has a constant 12 volts supplied to the exterior lamps ... so all it takes is a shorted base for a constant drain.
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The other possibility is relays that are not "falling" out. Look though all the relays to make sure none is staying "on" .... all it takes is a stuck relay contact and you have your symptoms.
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good luck!