Unlikely, unless someone else is nearby (about 1/2-mile) on your frequency. Radios don't go bonkers just from setting around. Are the transmitter batteries fresh? Are you sure it's the right radio & freq?  

Another device emitting RF, like a lawn mower, string trimmer, ham operator using illegal power amplifiers, etc., could cause interference. Cell phones, especially when ringing or ending calls, have been known to interfere with 2.4Ghz RC radios. Is there any possibility your receiver got wet at some point, or has been dropped?