The PCR "test" is not based on viral RNA. For example, if we look at the WHO protocol ( https://www.who.int/docs/default-source/coronaviruse/... ) and pay attention to the second primer (CTCCCTTTGTTGTGTTGT) and then go to the so-called Gene Bank, to the page where the 8th chromosome is described ( https://www.ncbi.nlm.nih.gov/nucleotide/NC_000008.11?... ), at the very bottom we see the exact same sequence. That means we are being tested for our own DNA.
The WHO protocol is not used everywhere, the primers differ from country to country, but this does not change anything since the origin of other sequences is not known, there are no scientific publications whose authors approach the isolation of SARS-CoV-2 in a scientific way. Yes, Peng Zhou, Na Zhu, Jeong-Min Kim, McMaster University claim to have isolated the virus, but if you look at the "isolation" process, it is clear that purification and isolation are out of the question: they either don't filter the pulmonary fluid, or, having filtered it, they mix in Vero cells, liquid fetal calf serum, and antibiotics, in response to which the cells secrete extracellular vesicles. Dr. Andrew Kaufman has analyzed various German PCR testing protocols, and many of the primers mentioned there had an 80%-85% similarity in the genetic sequence to certain parts of the human genome. The number of cycles + the amount of genetic material in the sample will play a big role in determining whether you are "sick" or not.