I would quite agree with what the others have written so far; try to avoid the problem by either positioning your subjects in a way to avoid the issue or try to adjust your shooting position to ensure that it doesn't happen. As others have already suggested, post-processing tools can help here.
Here is a shot where I was too busy concentrating on taking the picture to notice the issues in the background (light sticking out of the head and another one on the right of the subject). Two or three minutes in Photoshop CC and the offending material was removed:
Before:
After: