Fox in the house? Nah, no problem. SO long as it's not around any pets it could harm, of course. Worst that will happen is it'll bite me, maybe leave a scar, I won't know if it's rabid, and I'll have to go get a rabies series. I hear they don't have to do those in the stomach anymore, so I'm no longer afraid of those. (And, if they DO still have to do in the stomach, let me remain delusional about it.)
Seriously, the only animals in the U.S. that I'm truly afraid of are Bears, Mountain Lions, Rattlesnakes, and Water Moccasins. Copperheads no longer scare me. After 17 years at my last home, I got to where I would just walk around them most of the time, so long as they weren't on the porch or in the house or something. (Yep, had a copperhead in the house once. The cats were PLAYING with it. Found snake skins in that house 3 times, too...) Coyotes & wolves don't scare me, so long as I don't have animals loose outside that they could eat.
I'll take a fox in my house anytime, rather than picking something up from a closet and finding a HUGE snakeskin...
Now, a bear in my house? That's another story. Had a family member who lived for years in an area with a lot of problem bears. They had bear get in more than once...