I was surprised to see this in my yard. I was planting a lupine I'd grown from seed. The lupine had been in a 4-inch pot with potting soil in my greenhouse for the preceding few months. When I removed the soil + plant from the pot in order to plant the lupine, this silverfish fell out of the potting soil onto the ground. I'm pretty sure it wasn't on the ground already (where I'd just dug a hole for the lupine). It seemed to come from the pot. Either way, my yard in the Bay Area, and especially a pot from my greenhouse with store-bought potting soil, seems like a strange place to find one of these silverfish.