This is used for an electric shock, but I want to depict a small static shock, which is several magnitude weaker than a full-blown electric shock. I am not sure how to do this. I want to tell the readers, it's a barely noticeable shock. I thought about just making the character mention it, but that's telling and not showing, so showing would be better, but I just don't know how.
One approach, is to do it like in the Garfield cartoon below, and use small sparks and a sound effect.
But I think just showing the character reacting to it would also be fine, especially if you show the lead-up and it's clear what's happening. If you see person A charging up static electricity and then touching person B, and person B suddenly jolts/tenses/straightens and turns and goes "WTF man!", then even without showing a spark or using a sound effect, it's pretty clear what happened.