yes I have and also concerns for violent resident roommate as well. and when calling for help last night via walkie, no one came. lead said she was with a resident and couldn't help.
Okay, so that was last night. If your Lead was with another resident, then no she couldn't just leave that person; but what happened next? Did she turn up eventually?
What is this person actually doing, the one who is causing the problem?
On the other hand, why isn't the resident or residents agitation and violence being addressed? Perhaps medically? I think there are creams that can be rubbed on the wrists that are calming? I may be mistaken about that, but still.
I tried googling "can a cna refuse to care for violent patients" and came up with some interesting reading, including a very good training pdf from RN .com on Dealing with Assaultive Behavior: An Overview for CNAs.
Have you already discussed your concerns about your safety with your manager?
What is this person actually doing, the one who is causing the problem?