2010 Chrysler Sebring trunk pops open at random

For the past couple of months, the trunk of my car randomly pops open. A few times my neighbor has called to let me know it’s open again and he has closed it himself on a few occasions. I asked my mechanic about it and he said he was at a loss.
I now go out and check the trunk several times through out the day. Any ideas on what is going on or how to fix this?

does your key fob have a trunk release? Could someone be sitting on it?