All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
Wearing the Hijab is an obligation set by the Sharee'ah. Allah Almighty has imposed it on the Muslim woman. So she is Islamically obliged to wear the Hijab whenever she goes out of her house. The obligation of wearing it is not something in which there is room for tolerance, and a woman is not allowed to give it up.
If you mean that you want to wear a wig before non-mahram (permanently unmarriageable) men, then you should know that you are not permitted to do so, because the aim of covering the woman's hair is to conceal her adornment. This, however, can not be achieved by wearing a wig. Mere looks of estrangement on the part of people do not allow you to do this. If there is no necessity for this work or a considerable need which is valid in the Sharee'ah, then you are not permitted to keep this job. A Muslim woman is not allowed to work in a place where she intermixes with men, and it is better for her to stay at home.
If you mean wearing a wig before other women, then there is no sin involved in doing so. Some scholars are of the opinion that just putting hair on the head without fixing it to the natural hair, as is the case with a wig, is not included in the forbidden fixing of hair extensions.
Allah knows best.