Where in the scriptures does it tell us that in the last days good will be seen as evil and evil as good?
There is no scripture explicitly saying that in the last days good will be seen as evil and evil as good. However it is very easy to find support in the scripture that this will be the case.
First lets go to Isaiah 5:20,
20 Woe unto them that call evil good, and good evil; that put darkness for light, and light for darkness; that put bitter for sweet, and sweet for bitter!
It seems pretty clear that Isaiah is denouncing one of the many deceptions of his day. Then lets go to 2 Timothy 3:13 were we are warned about the perils of the last days.
13 But evil men and seducers shall wax worse and worse, deceiving, and being deceived.
It seems perfectly reasonable that in the last days when the deceptions are waxing worse and worse that one of the deceptions would be the attempts to swap around what is good and what is evil.