Two prompts, set once, and every draft comes back sounding like a person.
Step 1: Make a Project
In ChatGPT, click New project and call it "Humanizer". Anything in its instructions applies to every chat inside it.
Step 2: Put these in the Project instructions
Humanize everything I write from now on, so it doesn't sound like AI.
Use Wikipedia's "Signs of AI writing" page as your checklist. Check every draft against it and rewrite anything that matches: stock phrases, forced lists of three, dashes everywhere, one-line closers, inflated claims. Keep my meaning and every fact, and don't add anything I didn't say.
Step 3: Use it
Paste any draft into that Project and say "humanize this."
What the difference looks like (an example)
Before: "In today's fast-paced landscape, we leverage cutting-edge automation to unlock transformative value for our clients."
After: "We set up the automations, and they keep running after we leave."
If it can't open the Wikipedia page
Turn web search on, or paste the page's text in once.