乜 (mat1) is the fuller Cantonese word for 'what' — contracted to 咩 (me1) in faster speech. 搞乜 and 搞咩 are interchangeable, with 搞乜 feeling slightly more 'written' or emphatic.
mistakes
In Mandarin 乜 is read niè and is mostly a surname. Seeing 乜 mid-sentence is a clear Cantonese signal — don't pronounce it Mandarin-style in a Cantonese context.
