The gemara in sanhedrin explains that two strands of fire came from the kodesh kodashim and entered the sons of Arons nostrils and they were consumed. Why were they killed by these strands of fire? A gemara in eruvin explains that if one paskens infront of their rebbe they should be bitten by a snake,then they should have been bitten by a snake(gemara says this is what they were guilty of) why by fire instead? There is a medrash that says there was no snakes in the midbar because strands of fire consumed them. Since there was no snakes the fire which consumed the snakes was used(Tiferes Yehonasan)
In E”Y, if you keep one day of Yom tov, shemini was read last week and Tazria-metzora is this week. However, in chutz laaretz, Shemini is read this week.