black wire coming into house?
From your description, I would say they are Coaxial cable for cable or satellite tv. Some installers will put them next to an electrical outlet from the outside of the home because you will generally need to power a set-top box. If you look inside the house next to an electrical outlet, where this black wire seems to go into the house from outside, and have this or something similar:


then it is coaxial cable. Sometimes you will find just a short wire hanging out of the wall here. It is all up to the installer.