It is often possible to gain access to a building with a fake badge. Check
out if individuals leaving the site are still wearing badges. You can find
a wealth of these at lunchtime and after work and can often follow people
to gain access to their badges,
either to acquire them whilst they're in a public place or to
clone an RRID badge. Do not access any private spaces they
may enter, such as their homes.
It is perfectly fine to simulate someone losing a badge at a pub,
but not for breaking into the house. Ensure you have a letter of authority at
all times when carrying out this type of work or, again,
you may be arrested.