Regidoof

Hello my dudes. Recently read that there is an event in Peridot Ward at night where you get a 50% chance to find Joltik. They said there is a building where the lights are off and when you go there with a PokeSnack you can find it, though i have been searching every building for about an hour and cannot locate it. Someone said that you might have to go there before Corey's gym and I currently am at the Tauros riding spot. Can someone give me a hint cause i need a strong electric type Pokemon.