In our Church we have wireless Shure PGX series transmitter and receiver‘s. We use an ear Mic. In a 45 minute verbal presentation, there are sometimes five or six Popping, static noises that I cannot discover what causes it. In testing, if the pgx1 transmitter is totally motionless, there is no popping at all. I have disconnected the ear mic entirely and also while motionless, it’s totally quiet, if I rub my shirt sleeve over the transmitter, there will be a popping sometimes a couple times in one minute. But it’s not consistent and not predictable. Any suggestions of what it could be? Could it be static electricity causing it?