SSRS Optional Query Parameter

Hi,

I have this optional parameter was passing into my SSRS report.  What I have below is working fine, but I want it with like condition not =, not sure for syntax, can you please help me with this?

Thanks

Where item = isnull('''+@Item+''', item) 

i tired this, but didn't work either 

Where item = isnull('''+@Item+''', item) + ''%''