I have seen this before and all the above replies are correct; ground
fault (your ground wire has been broken or power is leaking to ground)
but there is one more possibility. Many people plug in power adaptors
for various things (shavers, etc.) that have no ground plug. They may
leave these adaptors in the outlet all the time. Sometimes the adaptor
will still work but inside it has failed and will cause a GFI reset.
Try unplugging anything plugged into your bathroom/garage GFI circuit
FIRST. Then see if your GFI circuit will hold a reset.

Jeff

wrote:
I have a GFI that won't re-set. It's in the garage, but also is linked
to the outlets in one of the bathrooms. Nothing unusual has happened.
I was working in the bathroom last night, but nothing today, and it
only tripped within the past couple of hours. I press the re-set, and
it pushes back against me. Any thoughts, or how I would troubleshoot
it? Thanks!