I am new & not all that clued up. Would love some help with something which is bugging me about my lovely bass... 
 
I have read as much of the forum posts as I can but would be really grateful, please if someone could kindly let me know what I need to do...I don't expect I will be using all the right terminology. 
 
I have had this bass for about a year - bought used and it's my first - but I really like the feel of it and the sound too. Cosmetically it is in great condition - holds tune well etc. 
 
The problem I am having with my Peavey is when I'm playing in a group at my church, where I plug into the amplifier & bass cab which is in situ there. 
 
When there are other amplified instruments or voices mic'd up within 10 feet of me, my guitar picks them all up & puts their sounds through the bass amp & speaker.   
 
All of these other instruments & mic's are on wireless. 
 
The other bass I have access to (a Fender P-bass which again resides at church) does not do this.  
 
I have to turn two of the three pots down to stop this effect,  which makes the sound very bland.  
 
I have taken the scratch plate on the front off & looked for loose wires, there's nothing obvious, and I noted that there was only a small amount of foil stuck around where the pots mount the scratch plate. 
 
Has anyone got any simple fixes for this ? Is it simply better shielding which is required ? Or am I in the realms of new pickups ? 
 
Many thanks.