Hi Linda... I was just looking / surfing and saw your comment. I'm not sure if you got any answers to your dilemma but here goes.
All wall outlets and switches need to receive a little preventive maintenance. Typically, in a sticks & bricks situation, every five years or so you remove the plates and tighten the screws as they do get lose from the heat generated with usage. That being said, you're always on the move so this needs to be done more frequently.
You could add this task to your quarterly preventive maintenance checklist.
I hope this helps your situation although it's probably too late for your current issue. But this should help with your ongoing maintenance.
Kat