What should I have an expert do to confirm? Is this dangerous?
An expert can only confirm that you correctly measured the 78 microtesla.
The World Health Organization estimates that the natural geomagnetic field is between 35 and 70 microtesla. 78 microtesla is higher than normal, but still unremarkable. When you're commuting in a (electric) train or working as a welder, you are exposed to fields that may be a thousand times larger. If magnetic fields were dangerous, you would expect welders, train drivers and plenty of others to die young. I'm not aware of significantly higher rates of cancer or other diseases for such professional groups.
The only known health issues at relatively low field intensities are:
For static electric fields, few studies have been carried out. The results to date suggest that the only acute effects are associated with body hair movement and discomfort from spark discharges. Chronic or delayed effects of static electric fields have not been properly investigated.
The same source mentions further effects like vertigo - but at 2 Tesla (= more than 10000 times the value that you measure).
Still, the absence of a proof of dangerousness is not the same as a proof of harmlessness:
It is not possible to determine whether there are any long-term health consequences even from exposure in the millitesla range because, to date, there are no well-conducted epidemiological or long-term animal studies. Thus the carcinogenicity of static magnetic fields to humans is not at present classifiable.
(Note that millitesla range is still at least a factor of ten higher.)
You're are certainly exposed to other environmental factors that constitute a much greater risk.
Can being above electric room spread EMF to unit?
You can shield electric fields and also high-frequent magnetic fields, but it's almost impossible to shield from static magnetic fields. You may at most deviate the field by some degree. So, the answer is "Yes", even if I wouldn't use the word spread in the context of static magnetic fields.
And would my proximity to the electrical room at this field charge the metal in my unit? Faraday’s law? It would explain the excessive static electricity, no?
Faraday's Law is (almost) irrelevant as it doesn't apply to static fields. I don't think that the static magnetic field has much to do with charging your metal items.
Maybe transient / higher-frequent magnetic fields play a role, but I would look for other culprits first (faulty electrical installations, carpets,...)