Not everyone on "Myrtle Manor" spends their days getting arrested ... fact is, two "Myrtle" stars are too busy raking in the cash.

Gina (a.k.a Miss Gina) and Roy (a former drag queen) co-own Tangulls -- the only hair salon inside the trailer park -- where all the cast members get their hair did.

Our trailer park spies tell us ... Gina & Roy's biz has seen a 300% increase since the premiere of the show -- and there are now endless lines, with up to 300 people a day showing up from all over the U.S. of A..

Business is so brisk, supply can't meet the demand ... G & R can only chop the locks of 25 people a day. Some fans actually extend their trips to get that special cut.

Now here's the kicker. Gina and Roy have no plans to raise prices or move out of the park.