I think compulsive behaviors may be symptoms of a hidden trauma. Such behavior as intrusive checking may be associated with feeling of insecurity. Possible to solve the problem rather through deeper discovery of the problem, not superficial changes. Otherwise, trauma will apprise about itself, causing other problems.
I think that that could be my case, I do have this tendency to check out certain things, I had been having improvements and depends in which state of mind I am at the present of doing mechanical things, I do concentrate and try to not think in other things, as turn off the oven, check the door is closed ... mostly they are regarding security issues? and mostly regarding other people's things that I am using, like the apartment which I am staying (doors, oven, boiler, windows, plugs, tv). If I feel fine with myself do not need to check it compulsively, but if I am anxious state, not trusting other people and along of not trusting myself and overall negative thinking, so it is for sure that I check them more than 3 times.
I think I started with the iron (for cloths), it was like 10 years ago (in short, I was lost and my selfsteem plumed at that time), so whenever I use the iron, I checked it out like tree times to be unplugged and cold, sometimes I was away from home and I did came back to check ti out, of curse that mania worsen through time because I started with other things. Like if I closed or not the door of the garage. I am saying I think I started with the iron, because there is a story behind it:
I may had like 10 years old, I was in company with my brother and two cousins at their room playing with a iron-toy (that needed to be plugged) so, time passed and our parents called us to leave, our home was in front my cousins (in a private street like with 8 houses) and my cousins and their parents went to their grandparents to pass the night, early next day our neighborhoods alert my parents, that my cousins house was burning. Fortunately, the house was saved (being made of bricks); the fire started in my cousin's room, I remember being too shocked seeing how the house was burning -I supposed our parents asked us, the fire department said the iron started the fire.... -being kids- typical ... "unplugged the iron" said one to the other and ... no one unplugged it. I do not remember if our parents said anything, like grounding us, but my self steem at that time was not good, I supposed I felt responsible of burning my uncles home --I know now that I was not responsible at all-- but I do not know how to "go into the past and erase that thought" and that's why I keep checking and double checking stuff. And keep observing the why, the when, .... last time when it was more, intense? my parents were around.