Sometimes these schemes are perpetrated outside of section 8. I was president of a tenant's association in Princeton NJ during the transfer of a complex from rental to condo. The local Democrat politicos attempted to insert affordable housing grantees into the mix without telling the proposed condo purchasers. The plan only failed when the scheme was exposed by yours truly.
I'm sure this kind of thing happens all the time.
A hidden aspect is that those chosen for such affordable housing tend to be Democrat county committee people or relatives of public figures. This led me to christen the program, "Awardable Housing."