I'm not sure what corporate can do here. People do weird things at weird times and there are no rules that will prevent that. Making sure the door is locked from the inside whenever you're in the room is always wise. Now if housekeepping (regular staff) has override keys, then talking with the GM would be the right thing to do. Making sure your door is securely latched when you leave is important to do. Many times I've had the closer not seat the door completely so just pushing on the door will open. Again a comment to the front desk will probably/hopefully get a maintenance request posted and addressed. Ultimately the property is the one responsible for on-site security issues and best addressed locally.

A case in point, I received a second charge from a property for a movie charged to my room. It turned out that happened after I checked out! When I was talking with the manager I suggested maybe someone slipped into my room while the door was propped open during cleaning. She was emphatic about that does not happen there. Next time I stayed (yes, I give second chances), I noticed several doors with the flip locks propping doors open, so I went to the front desk, asked for the manager and if she'd take a walk with me down the hallway. She was very angry to see the doors opened and promised to address the issue with the staff that day! The next day there were no doors open when I walked down the hallway. So give the local management a chance and if they fail to take the issue seriously, then escalate with someone at corporate operations.