Welcome to Nestwell Property Managements 24/7 DIY Maintenance Center. Thank you for your question about your garage door opening randomly.
This is a “fun” experience. It doesn’t happen often, but it does come up every once in awhile. The most likely explanation is that a neighbor’s garage door opener and yours have gotten on the same frequency. Their remotes are opening your door and vice versa. You will need to reset the frequency on your garage door opener and program the remotes to the new frequency.
The following video will show you how to do this: