Should I cancel my insurance plan? I am reaching 55 next year, i am considering whether to cancel my WL insurance which i have brought in year 1985 and put it into CPF to earn 4% interest. Is it a good idea?

You have to do your opportunity cost analysis.

You can write to us with your policy and we may wish to takeover your whole life plan.
https://www.policywoke.com/sell-to-us

As someone who has been in the insurance industry, I would say that Whole life insurance are not meant to be an investment product. The cash value inside a whole life plan (3% on average) is inferior compared to investing (at least 3%). Hence, I would definitely recommend you to buy a term and invest the rest.

However, do note that you are already at the age of 55 and buying a term plan now might not be worth it since the premiums are higher at older age. Additionally, if your Whole life plan has already been fully paid and building up cash value, you can keep it till you are at retirement age to use that amount of money. That is, if you have no one to leave a legacy behind for.