I suspect there are a lot of bad actors who are after his a$$ and Melania would be the least of his worries.
Trump had SS yank H's protection when he found out SS had sent something like 20 agents to South Africa when he fled the country earlier this year to avoid a deposition. Presidents and First ladies get lifetime protection. Family members only get 6 months after the President leaves office. If H wants SS protection, he has to live in Mom's and Dad's basement.