I am 24 and having wet dreams from last 7-8 years, 2-3 times a month regularly, is it normal? I do masturbat sometimes. What should I do to stop them.

Sexually active. The only way to stop nocturnal emissions (wet dreams) is to masturbate more or have sex.
Controlled release. In teens & 20s this can be normal. Can reduce this by "controlled" or "planned" releases -- either via sex (use condoms if don't want parenthood or stds), or masturbation.
Sex or masturbation. Need a sex partner, or masturbate about twice a week which will take care of this problem. Your body is continually producing semen, the ejaculatory fluid produced by seminal vesicles, prostate & coper's gland. Build up has to be released either voluntarily or occurs during sleep as a wet dream. Good luck.
Good for you. I'm really sorry that anybody has made you worried about your nocturnal emissions. They're natural, healthy, and you are supposed to enjoy them. They'll be less frequent if you get a partner or are more willing to enjoy yourself when you're alone -- think about wholesome loving rather than internet trash. This is the 21st century, and old superstitions should be forgotten. Best wishes.