This is in the southern US (northern Alabama). I’ve seen this insect a couple of times inside our house, and also a couple of times outside. It’s about 3/4 inch long, maybe a bit less. Initially I thought it was a firefly (lightning bug) but it’s flatter, walks fairly fast (though not difficult to catch), and does not have translucent segments in the abdomen.
I guess the real question is, is this a household pest I should be worried about, or a harmless outdoor bug that has wandered inside?
Never mind, found it: Pseudomops septentrionalis - Pale Bordered Field Cockroach.
Orkin says they "normally live outdoors and are not considered to be a serious indoor pest. "
Normally refer to them as Palmetto Bugs or “big ass cockroaches” in Florida, though it’s pretty much understood that they’re not the same level of pest as normal cockroaches. They can usually be found indoors after a hard rain, but they prefer to live outside.
The term “palmetto bug” seems to apply to the American cockroach and the Florida woods cockroach. What I’m talking about is much smaller - they really are the size and color of fireflies.