My 7 volt project calls for a .1uF capacitor.
All I can find is a .1uF 1KV and a .1uF 50v
Will either one work?

 

Yes. That is the breakdown voltage, which is the point at which the capacitor may fail. Since you are operating at 7V go with the 50V one, as it will be much cheaper and smaller.

 

ThANK you!