I would have to know a few more things to be able to give you an adequate answer. By lodger, do you mean "tenant" or are you renting out a rooming house? If its a rooming house, I would want to check with the Town of Easton as to whether this is a permitted use before going further.
Otherwise, it sounds like your tenant is a tenant at will, meaning he is entitled to a thirty-day Notice to Quit the premises. Once the thirty days has expired if he still has not left the premises, you can bring an action to evict him. It is called a "summery process" action and will be through your local district court.