I have a strange problem with my garage door: come home from work my garage door is open. This doesn’t happen often and fortunately I don’t live in a neighborhood where I have to worry. Still it’s unnerving and people can still see all my stuff.
This is a strange one and I’ve seen it only a few times in my years fixing garage doors. There are a number of things that you can check. First, there is a close switch that is supposed to be tripped when the garage lowers to the ground. When you hit the ground, it should shut the opener off. If it’s set to shut a little lower than reality, you might need to adjust it. What I would do in this case is reset then entire door and start from scratch.
Another problem could be a circuit board gone bad. If you have any extra remotes in the garage they can mess with the door.
One other thing that can cause this is if you live near an airport or an air force base, these guys have some heavy duty equipment that can effect things for a few miles near the base.