I have a new house with metal roof no plywood with Ridge vent and soffit venting and has cathedral ceiling. My electricians vented the bathrooms high up into the attic, is that ok?
Electricians are usually only responsible for supplying and installing the fan, not running the ductwork. That is usually done by the HVAC guy or at least another trade or individual. If the electrician has it there contract to run the ductwork fully, then it needs to go to the outside of the house. The water vapor from the bathroom will condense under the metal roof on cooler days and cause water damage elsewhere.
For years and years we vented exhaust fans up to and in the vicinity of a roof vent and fairly successfully I might add. However, by modern standard that method simply doesn't cut it. Even if you need to get a roofer involved, exhaust fan venting should be terminated to the out-of-doors. Additionally, in our area, insulation is now required around the venting material itself. In extreme cases of long horizontal runs, condensation can occur within the venting itself. However, as long as the vent line is kept as short as possible and as vertical as possible, I don't have condensations problems with non-insulated vent lines. I do however vent everything to the out-of-doors. (I happen to do a lot of retrofit bath fan installs) Cheers & happy venting.