Considerably more information is needed before an answer other than "don't do it" is offered. Do you wish to replace an existing light fixture with sockets, to be controlled by the same switch that turned on the light? Do you want to run wire from a switchbox to a new or existing socket?
Concerns include making sure the ratings of all devices (switch, wiring, and socket) are sufficient for the intended load. If running to an existing outlet, you also need to make sure that any existing wiring to that socket has been disconnected and removed or capped and wrapped; leaving it in place is asking to be electrocuted when you've got one current source turned off, but there's another.
There may also be grounding issues; make sure the outlet and its box remain grounded for properly safe operation.
Unless you are certain you know what you are doing, this is the kind of job best left to a pro; the money saved won't be worth the risks you take, whether now or over time as the circuit is used.
Besides which, it's likely you CAN'T do that anyhow, unless the neutral wires are present in the switchbox, which they are not always. Often, only the hot and ground wire is present in the switchbox, to break or make the connection, and the neutral wire is only present at the light or outlet, or bundled with other switch connections elsewhere, which the switch is intended to to control.
That means you'd need to also reconfigure the wiring at the point of that device. In some cases, it might be reverse of that as far as which wire is used to break the connection but I think that's been standard across the board for a very long time.
As mentioned, if you don't know how to answer your own question, then it's a very bad idea for you to undertake this yourself. There is incredible opportunity for harm or fire to occur, to yourself or your house, not to mention it will violate code and if you (Or the owner) ever need to sell the house and it's determined that the modification does not meet strict electrical guidelines, you will still have to hire a licensed electrician to fix or verify the validity of the modification anyhow.