This is likely a case of an infamous RFI problem. The spectrum is allocated to DoD, and garage door openers were allowed to use it provided they followed partic

This is likely a case of an infamous RFI problem. The spectrum is allocated to DoD, and garage door openers were allowed to use it provided they followed particular guidelines. Some follow them less faithfully and issues like this are the result. (There are other stories of equipment getting turned on that opens nearby garages with particularly bad implementations, but I don't know if they are true.)