I could not tell if it was a cricket or the smoke alarm.
I had smoke alarms on my mind. My smoke alarm did not go off yesterday morning when I had some smoke from overcooked food. I realized it has been too long since I replaced the batteries.
So when I heard chirping I thought maybe the smoke alarm finally decided to go off. It was slower and quieter than a smoke alarm normally is, but I attributed that to the weak battery.
When my smoke alarm goes off, I've always known that cause and known my house was not burning down, so the response is normally to go get the ladder and climb up the ladder to get to the smoke alarm, and then take out the battery. So I got as far as climbing up the ladder, but the sound just did not seem to be coming from the smoke alarm, so I left the battery.
I think there is a lost snowy tree cricket in my house.