I am looking for a scale of measure for "Social Media Self Efficacy", as I have found computer self efficacy but still falling short of self efficacy scale for social media.
I understand self efficacy to be the confidence with which users perform actions. Thus computer self efficacy will literally mean users ability to use computers confidently whiles social media efficacy is the confidence associated with the use of social media tools and platforms. It will rather be difficult to find exact items for social media efficacy since most directly relate it to computer self efficacy.
I'd advice that you should modify items for computer self efficacy to suit social media and probably test them using a point Likert scale to determine the clarity of those questions..