similar but, 싫다 can be used for anything including people. 나는 네가 싫다 = I dislike you. 나는 냉동식품이 싫다 = I dislike frozen food. But 밉다 can be used for only people. 나는 네가 밉다 = I hate you. 나는 전남자친구가 밉다 = I hate my ex-boyfriend. In English, you can say "I dislike to talk on the phone." and "I hate to talk on the phone." But we only say "나는 전화로 이야기하는 것이 싫다"(o) "나는 전화로 이야기하는 것이 밉다" (x)