Do you mean text with a stroke but no fill? If so, this is quite easy.
Write some text with the text tool and keep it selected. Go to the windows menu and open the character panel, if it’s not already open. Increase the width of the stroke. Make the fill colour active (top right of the panel) and then click on the small white bow below it with the red line through. This removes the fill.
Simon Bonner
youtube.com/simonsaysFX