Mic malfunction on tv

When a microphone malfunctions during a live broadcast and isn’t picking up the actor’s voice, often you hear the dialogue as if it were picked up by another mic somewhere in the area but not close enough to pick up the voice well. So you hear the person speaking, but at a much lower volume and lower quality than intended.

So where is the other mic and why is it on? It seems that the intended mic would be the only one activated and transmitting to the live broadcast, so why is there another one somewhere nearby that also picks up the sound in a much less effective manner?

Btw, this happened during Saturday Night Live last night, at the beginning of the white rapper skit.

Another actor’s microphone may be able to pick up the speaker if near enough. There may be backup microphones nearby or in the ceiling or something. In the SNL case, I suspect the mics used to pick up audience laughter might have been the live mics you heard.
I work an audio board and I usually have multiple feeds pushed up live apart from the main speaker. In any case, any sound is preferable to no sound, so any mic available would be used to pick up the speaker. Even if not pushed live already, the audio board operator should be able to push a feed up live almost instantly.

Ahhh, the audience microphone. That would make sense in terms of how it sounded distant but still audible.