16x2 LCD showing garbage values after switching relay

Use the stealth search box at the upper right and look for terms such as 'LED garbage', 'LED weird', etc.

I think Don meant LCD where he wrote LED.

Switching mains AC voltage is not my area of expertise, perhaps someone more expert can offer advice. But maybe suppressor capacitors on the motor and perhaps the relay contacts might help, and inductors are also useful for suppressing unwanted interference.