Wifi dongle for MacBook Pro (mid 2009)?

Hi. Wifi has died on my old Macbook Pro (too old to update to High Sierra!). As in I get the "Wi-Fi: No hardware installed" message. I've tried the various fixes hunted down on the interwebs (resetting PRAM and SMC) to no avail. OK, so I was thinking it would be cheaper to get USB Wifi dongle than spend money at the local apple repairer...as this is a backup computer only. I don't really know zip about dongles and whether or not this idea would work given the "No hardware installed" message (and the fact that I haven't ascertained if it IS a hardware problem or not), so wondering if

(a) would a dongle get around my "No hardware installed" problem and

(b) any dongle recommendations/

Thanks!