What kind of spider is this?
That is a Parson spider, Herpyllus ecclesiasticus (Araneae: Gnaphosidae).
The Parson spider belongs to a group of spiders known as gnaphosids. Gnaphosids are common ‘outdoor’ spiders which do not spin snares (webs) but hunt on the ground for their prey. The Parson spider is among the few that are occasionally seen inside. The parson spider is a medium-sized spider (1/2 inch long) with a brownish body and gray abdomen with a white band running down over half the length of its abdomen. Parson spiders hunt at night. During the day, they are usually found outdoors under stones or loose bark in silken retreats. Indoors, they hide under objects or in cracks or crevices.
Parson spiders normally enter the house near ground level and are normally encountered in basements, crawlspaces, and breezeways. These spiders occur in very low numbers, and usually homeowners encounter only one or two of them. These spiders are not particularly dangerous but they will attempt to bite if handled roughly.
Chemical control is not necessary unless large numbers are found. Treating basements and crawlspaces with a residual insecticide (like Ortho Home Defense Max) may help to reduce their numbers. Be sure to read and follow all instructions and safety precautions found on the label before using any pesticide.