When I was in Mindanao , Surigao del Sur, I personally see and help those who possessed by bad spirit, I observed that their voice will change, their eyes will become red, and very strong. . . that was in 90's , and unfortunately the 3 persons that I assisted , only 1 left alive. . . the other two are dead now . but during the time it was happened they recovered.
Never go near with a possessed person ones you are weak, physical, emotionally, spiritually there will be a chance that the other entity will transfer to you ...