Professional electricians have to work with active cables without disconnecting the power, as this can be the demand for work. They make sure that they are not grounded and that they provide the path to pass the current. Therefore, they find the right shapes when it comes to hot cables. Electricians have the difficult and dangerous task of working with “living electrical current”.
Because a simple mistake can have disastrous results, it's vital to learn and practice electrical safety in a religious way.