I'm an intern, and a teahouse adds commission 1800 in January, which is scary. Is there something fishy in this? Anxious for an answer,

You must first know whether that teahouse really exists.

Is it formal or informal?

Now the teahouse recruits tea artists, and the salary is good.

Some are much higher than this.

However, there are also many people who watch this and may cheat.

You'd better see if this teahouse is open for business first.