As has been mentioned, let Apple examine the computer.
Generally speaking, a tingling sensation is not unusual for certain computers and other double-insulated devices with a metal enclosure, where a two-prong non-grounded/non-earthed mains connection is used. This effect may be more prominent in areas with 230-240 V AC mains voltage.
Someone with the necessary expertise could use a digital multimeter to measure voltage and/or current. Do NOT connect the multimeter to the mains (wall outlet/socket).
With a multimeter set to the highest AC voltage range, one test probe would touch the computer enclosure and the other a grounded/earthed object (such as a kitchen sink). The multimeter may show a voltage anywhere from a few volts to something like 100 V AC or more (at least in a 230-240 V AC country).
However, a digital multimeter has a high input impedance, so readings may be unrealistic unless an appropriate load is used. From a safety perspective, the resulting current is most important. An old article Does a "tingle" mean your appliance is dangerous by Jim Rowe in Electronics Australia, August 1988 had more about this. Newer standards/reports/articles may provide additional information.