" Put simply, I'd say: "I need to get rid of that tick that is been biting me all day long." I wouldn't say: "I must be free from that tick." And that is why I might use "rid of" with a chilly, rather then "free" (it does not matter https://governmentecogrants.blogspot.com/2024/08/what-are-steps-to-apply-for-free.html