Is this the Vacuum Control Switch? If it is, what does it do?

http://images.cardomain.com/member_i...49_81_full.jpg

When I was removing the Cold Assist I noticed that this was not connected from the switch.

http://images.cardomain.com/member_i...49_80_full.jpg
Were can I find vacuum hoses and that T connector that connected these hoses together. Would there be a problem if these were not connected?
By the way, that cut hose is from the Cold Assist. I'm going tp block it off.

Thanks