I get a ripple effect on my tv when watching my virgin digital tv, how do i correct this?

I get a ripple effect on my television when watching my virgin digital tv, how do i correct this? i have tried another television and the same problem occurs. it occurs when there are displays on the television , e.g itv logos, virgin logos or bright images such as footy match screened at night.
Answer
Your tv could be by a speaker or the fusebox try moving it as electrical interference could be what`s causing the ripple effect on your tv