Last year, I bought two air purifiers, one for the living room and the other for the bedroom. I'm really happy having them since we recently experienced important smog and the incidence of forest fires aggravating the situation.
It is the fine particles, not visible to the human eye (smaller than 0.3 micron), that get deep into our lungs and bloodstream. These fine particles are the main health risk from wildfire smoke. Both of the purifiers which I have use a H13 HEPA filter that is effective in catching these tiny particles. There are several grades of HEPA filters, if you order an air purifier, make sure it's using the H13.
Here is a good description for this type of medical grade filter:
The owner of a leading air filtration company in Austria explains HEPA air filtration ratings and how HEPA filters can help prevent the spread of COVID-19.
www.air-quality-eng.com