Fire engines from Taunton were sent to a report of a caravan on fire at Otterford Caravan Site in Culmhead near Taunton at 22:02 last night (Monday).
On arrival the crews confirmed that this was actually refuse alight up against the caravan.
They extinguished the fire using a hose reel jet and confirmed that the caravan had been slightly affected by fire.
Devon & Somerset Fire & Rescue Service say the cause was believed to have been deliberate and police attended the incident.
Police are appealing for anyone with any information regarding the incident to call them on 101 and quote crime reference number 521 7033 296.