Mic on/off switch. Necessary?

I'm a virgin mic shopper. Purchasing my first Dynamic(probably the AKG D880M). I will only be using it in my home, no live performances in the long and distant future.

Now what are the advantages to having the on/off switch. I can imagine it would be useful when the odd PA feedback erupts. What am I missing here?
Thanks

It's not really necassary and most mics I've used don't have one. I think they sell an Shure SM58 with a switch now.

An on/off switch is not necessary at all.

Thanks gys, appreciate the feedback.

I like to have a switch, Just in case of feedback you can kill it before damage is done to the speakers :)

just point the mic at the floor (away from the speakers) and you are golden !

I don't like switch's on a mic either. It's just something that can break...

The on/off switch is really made for live performances with many mics... some of which aren't used the whole time. Say you have a back up vocalist in one song... you obviously don't need an extra mic on the entire time. Since mics will pickup any sound..... They may pickup extra noise or layer the guitar sounds from the amp in the PA... cluttering the mix in the PA. That's generally what the on/off switches are there for... but in a home application or small rig... they're not needed... Most small setups don't need them either... They can be handy in recording also... but they're largely uneccessary for anyone that doesn't have a big live rig.

When I used to do FOH sound I always used the "mute" button next to the volume fader !

If artists start mucking around with on/off switches stuff stops working at inopportune times, cues are missed and people get shouted at. This is usually because the person on the stage has forgotten to turn the mic on after turning it off.

I put gaffer tape over on/off switches these days.