I have Obsessive compulsive disorders are you familiar with that it is a mental disorder? 
Somewhat I have know a few people with OCD
Yes I have it bad at home from hand washing, checking if doors is closed or things just being out of place.
I notice when I get stressed I get a little OCD myself.  I obsess about whether I have turned off the iron or locked the door.
Yes it can be very hard to control at times and sometimes we be like do it makes sense but just can not help it.
From my own experience, limited though it is, I completely get it.  It is an overwhelming need to do the checking.  
It is kind of funny that what makes me calm sometimes is watching the Batman Beyond series and comic books lol.
No, makes sense.  That provides a distraction for you. Something else to keep your brain busy.
You are right and are very smart in cases like this it can be just our stress level alot of times inducing the events or OCD.
I always try to distract myself when I am feeling stressed and get into the complusive thought mode.