It is not possible to get a ninth badge in Pokemon FireRed. You can only get eight badges in Pokemon FireRed.
island? the fourth badge is in celadon
The 7th badge.
The 7th badge
The Thunder Badge
You can use the move strength in Pokémon to move boulders. You can use strength in FireRed after getting the rainbow badge.
The Rainbow Badge
viridian city
leaf
spoon!
island? the fourth badge is in celadon
The 7th badge.
Saffron city.
The 4th pokemon badge is given by Erika the Celadon City Gym Leader.
The 7th badge
The boulder badge, the cascade badge, the thunder badge, the rainbow badge, the soul badge, the marsh badge, the volcano badge and the earth badge.
beat the gym leader
beat all the gym leaders