I'm thinking of ghosting one of my closest friends.
Why exactly would you ghost one of your close friends?
I'm going to ignore my friend's calls and ignore his walks.
If there is a problem between the two of you, it would be healthier to communicate and work it out. You don't want to lose a good friend, and ghosting could end the friendship.
It'll never happen.
It could happen if you cut them off with no explanation. That's why you shouldn't write friends off without a very good reason. It would strengthen the relationship to work things out openly and honestly instead.