I'm curious if I have to be attacking for me to use this against personalities at home? I mean if I defend and send his guys home I can't use them?
Strength in the earth and No Hiding place
A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
I'm curious if I have to be attacking for me to use this against personalities at home? I mean if I defend and send his guys home I can't use them?
That is correct, when your opponent is attacking you, he is the Attacker and you are the Defender.
Both Strength in the Earth and No Hiding Place specify they must target the Defender's cards, which you cannot do thanks to the targeting restriction of Melee and Ranged Attacks (an enemy Follower or Personality without Followers.)