I had to photograph him in a pill bottle because he was so active. And fast! He's a male, and looking for a female, going by the swollen pedipalps.
I learned something, looking through BugGuide to see if I could identify him; male spiders often become emaciated while they're looking for a mate, because they don't take time to eat. The abdomen shrinks and shrivels. This guy was skinny; from the side, the belly is flat.
I released him outside the door and he raced away. Good luck, little one!