Don't call them PCAs-- it's a term out of the spinal cord injury/Medicaid world that will seldom bring you good candidates. I can't remember what I posted for but probably something like part-time aide...and then went into the description. If you are looking for someone more full-time, you may be pulling more from the semi-retired category. A lot of people (and remember, you don't need "experience" -- most of our helpers had none) pulled back from health care or school because of Covid. You just need to reach them.
Places to post/spread the word: colleges with pre-nursing programs, including community colleges; CNA trade schools, senior centers, churches, community associations, local Facebook/NextDoor/classifieds portals, LinkedIn local jobs groups....
Ideally, if you find one good person even if they are part-time, they have friends/networks... Then they can trade times among each other when needed.
You can check criminal histories and other evidence by Googling.
The local ALSA/MDA may have referrals though I didn't find any worthwhile.
Best,
Laurie