I am trying to identify this spider found indoors in a rural area near Kansas City, Missouri. I cannot recall seeing one like it in my 14 years of living here but I have now found 3 inside in the past week. The one in the attached photo I found in my bed when I woke up. I would estimate that it is 2-3cm, legs included.
Sorry to be so long; I just came across this question.
There are a couple of clues as to the identity of your spider - the two-toned color pattern, with mahogany legs and cephalothorax, and grayer abdomen being the most important one. The other is that you found it in your house. It's been my experience that these spiders are commonly found in houses at two times of year - the adult males in the spring, and the adult females in the fall.
The most important clue is hard to see in your original photograph, but I took the step of lightening it with the Photo app, to let me see the front of its cephalothorax (see below)
What you can see is that the eyes are arranged in a fairly straight line across the fairly flat face.
The other locally common two-toned (red-and-white or red-and-grey) spider, Dysdera crocata, has a very different face. Dysdera is a streamlined, 1950s style racing spider, with forward projecting chelicerae and a pointed-looking front end (see below)
You'll notice the pointy front end, and the way the eyes are arranged in a tighter, almost clustered, curved line.
Your spider is one of the Flat-faced Sac Spiders in the genus Trachelas. I'd say it was probably T. tranquillis, but there are a number of western species, and I'm not sure where the ranges go to. Here's a reference photo of a male Trachelas species to compare with yours:
Here's the Bug Guide link to Trachelas: https://bugguide.net/node/view/26206
Note that colors and light/dark shades are not necessarily going to be the same in photographs as in real life, even above that Trachelas (like Dysdera) shows a range of color from white to grey abdomen and from red to almost brown cephalothorax and legs.
It might be this one:Dysdera crocata (Woodlouse Hunter)
more pictures of this spider from different places in the link below.
I know this is a bit thin as an answer but i know very little about spiders in the US,if anybody has knowledge about this spider please feel free to add the information.