I grew up catholic in the Midwest. Yeah it's a thing some protestants believe. They think catholics worship Mary, the saints, and/or the devil. It's the sort of thing you see from the sorts of protestants who are fucking insane.

My great grandma's funeral was hijacked by the preacher to tell the catholic side of the family that we were all going to hell. She didn't even believe in that sect, my great aunt just abused her into it when she had dementia. It was the sort of sect where there's no drinking or dancing at weddings and women aren't allowed to wear panted garments.