The survey of 10,000 Saga customers follows Tory MP Andrew Bridgen's Bill, currently before Parliament, to make it a civil matter.
The Bill won the backing of many MPs and the government is considering supporting it, meaning it may become law.
Just under one-quarter (23%) want it to remain a criminal offence meaning that offenders could be jailed. However, 64% of those asked are against making the BBC entirely subscription-based.
Saga spokesman Paul Green said: "Many of our customers are concerned that time is wasted prosecuting people who haven't paid their licence fee."