Starting from hrev56231, Haiku nightlies have a new driver ralinkwifi.
The new driver is the result of the importation of these three different BSD drivers, rum, run & ural.
This is the first step and according to @waddlesplash, it needs more testing.
Not entirely sure if these are working as they were not really tested.
But they don’t seem to cause KDLs at least, so the worst that happens
is that the WiFi devices fail to work.
You can have a look at BSD man pages linked above to see if your device is one of those that are supported.
Please report any success and in the case it won’t work yet provide usual infos.