Because mounting options are limited, there are two different options I can recommend for your Maverick 88. The first would be to replace your forend with a forend that uses an integrated light such as the Adaptive Tactical EX Performance Tactical Light Forend (linked below). You could also go with a barrel clamp that has picatinny accessory rail and use any Streamlight light you prefer. My recommendation would be the TLR1. Email us at Techsales@opticsplanet.com for further assistance.
https://www.opticsplanet.com/adaptive-tactical-ex-lighted-forend-for-remington-shotguns.html?_iv_gun-model=mossberg-maverick-88-12-gauge