Electric current from hdmi

If i touch my hdmi cable's metal part while it's connected to my tv, then touch my pc case with my other hand at the same time, i feel current tingles from the hdmi. Is there potentially a grounding fault in my pc that could damage it's parts or is this a non issue? My living room sockets don't have grounding since it's an older house, so neither my pc or tv get grounding from them. The tv is a very new oled so i doubt it could be the problem.