Electric shock while touching camera while the phone is on charge

Either you have a really cheap USB power source, or your house wiring is faulty.

Is this an actual painful shock, or a tingling sensation? Tingling can be from parasitic energy picked up from the environment and is harmless. If it is a shock stop using that power source and outlet immediately, and call an electrician to check your house wiring. And check with Apple support:

• Click on “Support” at the top or bottom of this page
• Go to Contact Official Apple Support

Note that both of the above have options to receive a callback or chat

Thank you for participating in the Apple Support Community.

We want to make sure you reach the right team for help with your device. We recommend that you contact Apple Support directly. Depending on your region, you may be able to reach them here: Get Support.