Things are electrified in Pokémon GO thanks to the Crackling Voltage Event! Lasting until 11:59 p.m. local time on February 5th, Electric-type Pokémon will spawn with more frequency throughout the area, letting trainers catch more as they go about their day. On top of this are a number of event-related 7km eggs, special Field Research rewards, and unique raids, including ones focused on Tapu Koko!
https://screenrant.com/pokemon-go-crackling-voltage-event-guide/