First make sure that keeping a pet squirrel is legal in your area. Capturing wild squirrels is immoral and illegal in many places. Even though there are squirrel breeders, you may need a permit. Squirrels need stimulation, a special diet and appropriate housing. They are far from low maintenance. I would not recommend them as a pet.
Squirrels are cute creatures who wouldn't want one as a pet; however they may prove rather difficult. Anything can basically become a pet. Squirrels are nocturnal creatures and play at night while you sleep. They require lots of food and water. They will climb and shred furniture if given a chance.
No, squirrels are not meant to be domesticated and brought indoors. They also may have rabies which will harm and potentially kill other animals or humans, if bitten.
Although squirrels are neat and cute, they are not meant to be kept as domestic pets. They also require a special diet, squirrels have been known to eat insects, eggs, small birds, young snakes and smaller rodents.