When do you use the particles "ga" or "wo" for certain adjectives?


I understand the differences between using "ga" and "wo" for action verbs and
static verbs, but what about for adjectives? For example, typically you would
say Xが怖い, but I see several cases where it's written Xを怖い (sometimes before
something like と思う or と感じる, but sometimes even in these situations it still
uses "ga")

Some examples from a Japanese article:

Using "ga"

  * 結婚が怖い
  * 結婚が怖いと感じる理由を紹介します

Using "wo"

  * 結婚を「怖い」と感じる
  * 結婚を怖いと思う人
  * あなたは結婚するのを怖いと思いますか？

Is it sometimes "wo" when it's part of a phrase or are there any other clear
linguistic rules for the difference in usage here?

