Place names certainly change over time. There are many, many name changes and boundary changes. In cases where records indicate your ancestor lived or owned property in a place no longer on the map, you have to look for other, older maps. Older maps can be found in a variety of places. It shows place names, roads, mills, ferries and churches referred to in ancestral records but which are unknown today.
Libraries are great places to look for older maps.
Some university and college libraries are the repositories for great map collections and, contrary to some popular beliefs, these libraries are open to the public. Another resource is a gazetteer. Also sometimes referred to as a geographical dictionary, a gazetteer lists place names and can help you locate them. Using this book, I might be able to determine that Sans Souci, NC, was located in the N.E. part of Bertie County, and had a population in 1890 of 12. Armed with this information, you might learn even more about an old town or a ghost town by visiting or contacting the state archives.