Sometimes when I wake up in the morning, I find that the trunk of my 1994 cadillac deville concours is open. It shuts normally when I close it, the motor turns on and it seals itself. It has 137000 miles on it, what could it be????THanks

Check your battery voltage. I've seen low voltage cause weird things on these cars, especially older ones like yours and mine.

When should I check my battery voltage?

I'd do it the next time the trunk opens itself. With the car off, check it with a VOM across the battery terminals. You might also verify that the terminals are clean and tight.

hey, i woke up and my trunk was open again. I checked the voltage through the DIC and got 11.3. The cables on the battery are tight and clean, i didnt use a voltmeter because i was on my way to work.

That 11.3 sounds low. You might want to confirm that with a VOM. What is the charging voltage? Age and condition of the battery? Is there a possibility of a parasitic drain caused by a glove box or trunk light not shutting off?