oil like substance dripping from television

A friend and I wired his new house for cable using exterior coax his brother gave him. His brother worked for the cable company. We ran all the cables in the house to a second floor wall and hooked it all up. Within a couple of years the oil inside the coax started staining the outlet boxes and the sheetrock under the boxes in all the rooms.

Lesson learned don't use coax with oil inside it, inside the house. I tell this to suggest you look at the cable connection on the back/side of the tv. Just in case.