I'm in a 1 story craftsman house and have a bathroom vent that had no ductwork, just pouring wet air into the attic. The vent also didn't work well to begin with so we never used it and thankfully didn't have moisture problems in the bathroom and no signs of issues in the attic.
We're trying to setup the vent properly before renting and so we cleaned out the fan (it was incredibly dusty, totally clogged) and had a handyman run a vent for it so it's not just pouring into the attic.
Looking at options for where to vent it, turned out the house side/rim joist under the roof is super thick (>5") so other option is a gable ~15' away, through the roof itself (we're wary of putting holes in our roof, though we could hire a pro), or vent out the roof ridge vent. The only venting in the attic is a ridge vent, there's only one exposed gable and the soffit is quite difficult to access. Old house, solid wood, again thankfully attic looks healthy even after >100 yrs.
Venting the fan out the ridge vent seemed like the way to go, at least as an initial fix and down the line we could do a more permanent install. I'm wondering if this is even a reasonable way to vent the bathroom fan though. Will the ridge vent sufficiently remove moisture coming from the bathrooms vent? How close does the vent duct need to get to the ridge vent to accomplish that, within inches, 1ft or what (a handyman did a quick fix pointing some cheap ductwork up toward the ridge vent, flush along the rafter, but with a ~3ft gap which we figure is probably not ok long term)? Are there any issues with this idea given the only attic ventilation is the ridge vent?