I understand Intimidate using Strength as its skill when done in a manner of just looking scary enough to demoralize your opponent, but is there a way to use Charisma to intimidate with words? Aside from making a Bluff check to make yourself sound more dangerous than you might actually be, how would you intimidate someone by just having an aura of menace about you or demoralizing the enemy with a sort of quick "hannibal lecture"? I understand melee fighters being able to scare with their muscles, but what about casters who are just as dangerous with their minds?
Yes, there is a way.
Ever-helpful d20SRD tells us that Charisma is the default attribute for Intimidate.
Strength is not used for Intimidate at all, barring certain class features and/or feats. That must be a houserule, one which is fairly common but I personally don't care for in the least. Intimidation is about more than just being scary, it’s about using fear to get what you want.
A skeleton is scary, but it cannot leverage that to accomplish much.