How can I find a person who is in the military service?

Answer 1

Do you just want to speak to one, you mean? Just
walk through an airport, and you'll probably see one
in uniform there (or in other public places).

Answer 2

it all depends on what branch of service you are looking for. if you have a friend in the military they could help you out. each branch of service have their own email system and he/she could look in their global address and look the person up and the base there at.