It does not matter whether the experience is paid or not, if you have experience then you have experience. If it is voluntary/unpaid they even look on it more favourably as they will see that you have a genuine interest in working rather than just a monetary incentive (even if that isn't actually true). Also, what if they ask you to carry out a role that you highlighted in your fake role but do not actually have enough experience of having done it? You may find yourself struggling which can see you out of a job pretty sharpish.
Here is a pretty interesting article about lying on your CV about work experience from someone who works in HR -
http://www.forbes.com/sites/lizryan/2015/01/31/the-truth-about-lying-on-your-resume/#41611e617c3d"And even if false credentials get you the job, those untruths may come back to haunt you.
"You're subject to immediate dismissal if it turns out you misrepresented something," says Nason. If your company is acquired, for instance, the acquirer's HR department may perform an audit of its new employees. Or your background may be checked when you apply for a promotion. Former Yahoo CEO Scott Thompson, former Notre Dame football coach George O'Leary and celebrity chef Robert Irvine are just three of the people who made news when false background information cost them high-profile jobs." -
https://www.monster.com/career-advice/article/the-truth-about-resume-lies-hot-jobsSome other good sources to look at would be:
http://workplace.stackexchange.com/questions/21358/what-are-the-chances-of-faked-work-experience-being-discovered-what-would-the-ihttp://www.monster.com/career-advice/article/when-you-lie-on-your-resumeIt might sound appealing, but what about in the future when it costs you a job? If you have the experience and qualifications necessary then you're in with a strong chance without having to lie. You could always expand on the
genuine experience you have in a covering letter which could give you a competitive advantage and not come back to haunt you.
What happens if they search for information about the company and nothing comes up? Or they contact a company with the same name and they say you've never worked there? Lying about what tasks you carried out is one thing, but making up a company and a job role is huge. It makes the application fraudulent e.g they may pursue charges if they find out after they have hired you, blacklist your name, or fire you. There is no good outcome if they find out, they're not going to tell you off and say don't do that again. That's it, you're out and it can affect your application to future jobs even out with that company.
Saying that, my mum *apparently* knows someone who has said they lied about a qualification to get into a job so eh. Your mileage may vary, although she did later go on and genuinely get that qualification. I definitely would not recommend it and the majority of people would also be the same. Sure, the chances of them finding out might be slim, however the consequences if they do find out can be huge. It may not just affect you in regards to that company but also future companies. Do not do it. If you need more experience on your CV then genuinely go out and get it, and it'll be a lot better for you.