1) -то added to relative/interrogative pronouns makes indefinite pronouns as like as in English adding "some...":
кто - who, кто-то somebody
где - where, где-то somewhere
почему - why, почему-то - for some reason
какая- which, какая-то - of some kind
etc.

Глупость какая-то
means "It's a stupid thing of some kind" or "It's a kind of stupid thing"

2) with other words -то has a meaning of emotional emphasis and is used in colloquial speech.

На себя посмотри, - фыркнул Игорь. - Я-то - в отличной форме.

"As for me, I am in excellent shape"