Yes for plumbers/electricians. Pretty much any business can qualify.
Q2. Who may take the section 199A deduction?
A2. Individuals, trusts and estates with qualified business income, qualified REIT dividends or qualified PTP income may qualify for the deduction. In some cases, patrons of horticultural or agricultural cooperatives may be required to reduce their deduction.
Q5. What is a qualified trade or business?
A5. A qualified trade or business is any trade or business, with two exceptions: