Are we supposed to isolate a weak MP limper from the SB?

[Allday Everyday]

I am wondering how often players in this forum raise from SB when there is a single weak limper to you. I find myself raising here with standard C/O and button isolation hands such as KT, suited aces, and even hands like 44. Sometimes I raise with less than these holdings. Should I be tighter, should I be looser?

What kind of hand do you raise in this situation? What is your specific range? Let's say all we know is that the EMP limper has a VPIP of 45 and is loose passive postflop, the BB has a VPIP of 25, and the small blind post is half the size of the big blind post.